
'I STARS 





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MAP OF THE STARS, 12 P.M., APRIL 



SUMMER 



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MAP OF THE STARS, 12 P.M., JULY 



SECRETS OF THE STARS 



BOOKS BY INEZ N. McFEE 

SECRETS OF THE STARS 

STORIES OF AMERICAN INVENTIONS 

BOY HEROES IN FICTION 

GIRL HEROINES IN FICTION 

BOYS AND GIRLS OF MANY LANDS 

LITTLE TALES OF COMMON THINGS 

A PEEP AT THE FRONT 

A TREASURY OF MYTHS 

A TREASURY OF FLOWER STORIES 



THOMAS Y. CROWELL COMPANY 



SECRETS OF THE 
STARS 



BY 
INEZ N. McFEE 

Author of "Stories of American Inventions," "Little 
Tales of Common Things," etc. 



ILLUSTRATED 



NEW YORK 

THOMAS Y. CROWELL COMPANY 

PUBLISHERS 



i i i i i 



Q^e- 



Copyright, 1922, 
By THOMAS Y. OROWELL COMPANY 



A681962 



PRINTED IN THE UNITED STATES OP AMERICA 



SEP 27 1922 



PREFACE 

Emerson once said: "If the stars should ap- 
pear one night in a thousand years, how would 
men believe and adore, and preserve for many 
generations the remembrance of the city of God 
which had been shown!" 

But the stars are so common; we may look at 
them on every clear night, so the most of us pay 
them small heed. In all ages, however, there 
have been observing and thoughtful ones who 
have sought to read in the stars the answers to 
various questions about the Universe, until at 
the present time the world is dotted with observ- 
atories equipped with a great variety of instru- 
ments for studying the celestial bodies, and as- 
tronomy has come to be regarded as the golden 
chain between the Earth and the heavens. In- 
deed, so closely does it bind the two, that the one 
is mapped by means of the other. By the wise 
guidance of the stars, fleets and caravans are 
sent over wastes of sea and sand which would 
otherwise be trackless and impassable. By the 



vi PREFACE 

stars are our clocks and watches timed, our lands 
surveyed, and the boundaries of our nations 
reckoned. In their twinkling faces are recorded 
not only the past and future of the comparatively 
small mud-ball which is our dwelling-place, but 
therein is also revealed the marvelous creation of 
the whole vast Universe. There is scarcely a sci- 
ence or an industrial activity of any kind that has 
not depended upon the revelations of starlight 
for its advancement. In truth, there is not a 
civilized person anywhere in the whole wide world 
whose life is not rendered more worth the living, 
or whose comfort is not affected, at least indi- 
rectly, by the work of astronomers and others 
who are applying the principles of this science 
to the practical affairs of daily life. 

And yet so used are we to taking everything 
for granted, that, to most of us, the rising and 
setting of the Sun, the marvelous phases of the 
Moon, and the march of the glittering star hosts 
across the sky excites no wonder and inspires no 
awe in our breasts. We are dead to the won- 
drous truths, more glorious than any tale of mys- 
tery or romance, that are spread continually be- 
fore our eyes in the great book of the sky — God's 



PREFACE vii 

own clear page. Our painted American savages, 
the Arab in the desert, the simple, ignorant chil- 
dren of the race on the banks of the Nile, the wild 
men on the islands of the sea, have all been more 
observant than we as a general people are to-day! 
It is impossible to read the literature of modern 
times without stumbling upon references to star 
legends which have been handed down since time 
immemorial. They are the efforts of primitive 
man to understand and explain the wonders 
which they saw all about them. They constitute 
the poetry of the sky, which we shall certainly 
find delightful, even if our minds are so consti- 
tuted that the drier, more scientific facts of as- 
tronomy do not appeal to us. Let us, then, 
rouse ourselves and at least make friends with the 
mysterious giant figures that people the blue 
dome of the sky! Once we learn to look upon 
these and to recognize them as the faces of our 
friends, we can but be interested in the countless 
things they have to tell us. 

Nor is any apparatus really needed for our 
study of the stars, save that which Nature sup- 
plies — a good pair of sharp eyes. Remember, 
telescopes, while they may add greatly to the in- 



viii PREFACE 

terest, were invented no longer than four hun- 
dred years ago, and all the planets and most of 
the stars that are now known had already been 
discovered and named. Likewise, too, countless 
of the most unfathomable mysteries of the skies 
have been discovered by no other aid than a clear 
eye and an inquiring mind. Have you these? 
Join hands, then, my readers, and let us go pros- 
pecting for the secrets of the vast suns of space 
— the boundless stars — which populate "the in- 
finite meadows of Heaven." 

The author gratefully acknowledges her in- 
debtedness to the many published works on as- 
tronomy which are available, both for the begin- 
ner and advanced student in this fascinating sub- 
ject. Authorities and works are cited in the text, 
but special thanks are due to Messrs. Cassell & 
Co. Ltd. for courteous permission to quote from 
Ball's "Starland." 

I. N. McF. 
Springdale, Ark. 

July 1, 1922. 



CONTENTS 

PAGE 

What the Stars Are 1 

The Sun, to Us the Greatest Star of All . . 21 

Mother Earth, a Chip from the Sun-Star . . 44 

Something About the Other Planets .... 67 
Mercury, "the Sparkling One" 
Venus, the Evening Star 
Mars, the Red Planet 
The Asteroids 
Jupiter, the Giant Planet 
Saturn, Uranus, and Neptune 

The Moon, a Daughter of the Earth . . . .119 

Comets, or the Ghosts of Space .. . . . .135 

The Nebulae or Fire Mist . . . . . . .158 

Shooting Stars 169 

Colored and Double Stars ....... 182 

The Milky Way 191 

The Constellations and the Zodiac .... 200 

Principal Stars and Planets 245 

Glossary of Terms 253 

Index .,.,,. ... . . . 265 



IX 



"Ye stars! which are the poetry of heaven! 

If in your bright leaves we would read the fate 

Of men and empires — 'tis to be forgiven 

That in our aspirations to be great, 

Our destinies o'erleap their mortal state 

And claim a kindred with you; for ye are 

A beauty and a mystery, and create 

In us such love and reverence from afar, 

That fortune, fame, power, life, have named themselves 
a star." 

— Byron: ChUde Harold's Pilgrimage. 



ILLUSTRATIONS AND DIAGRAMS 

Map of the Stars, 12 p. m. April] 

I Front end-leaves 

Map of the Stars, 12 p. m. July J 

Saturn July 2, 1894 Frontispiece 

A Great Sun Spot, Sept. 11, 1898 34 

Solar Prominences, May 23, 1900 38 

Solar Corona, April 16, 1893 and May 28, 1900 . . 39 

Eclipses 60 

The Four Seasons 61 

Comparative Sizes of the Planets 68 

Orbits of the Inner Planets and the Outer Planets . 69 

Map of Mars 1896-97 94 

The Moon: Third Day . .132 

The Moon: Region of Clavius and Tycho . . .133 

Three Forms of Path Possible to Comets . . . .144 

Comet of Donati, Oct. 5, 1858 . 145 

The Great Nebula in Orion . . . . ... . .158 

The Great Nebula in Andromeda 159 

An Irregular Nebula in Cygnus . . ,. . . .167 

The Milky Way Around the Star Cluster Messier II 193 

The Pleiades 204 

The Great Northern Constellations . . .... ... . 205 

xi 



xii ILLUSTRATIONS 

Constellations I: Auriga, Aquila, Bootes, Canis Major 214 

Constellations II: Coma, Corona, Cygnus, Delphinus 215 

Constellations III: Draco, Hercules, Hydra, Lyra 222 

Constellations IV: Ophiuchus, Orion, Pegasus, Phaeton 223 

Signs of the Zodiac .......... 232 

Constellations of the Zodiac I : Aries, Aquarius, Cancer, 

Capricornus 233 

Constellations of the Zodiac II: Gemini, Leo, Libra, 

Pisces 236 

Constellations of the Zodiac III: Sagittarius, Scorpio, 

Taurus, Virgo 237 

Map of the Stars, 12 p. m. October 1 

> Back end-leaves 
Map of the Stars, 12 p. m. January J 



SECRETS OF THE STARS 

i 

WHAT THE STARS ARE 

"Silently one by one in the infinite meadows of heaven 
Blossomed the lovely stars, the forget-me-nots of the 
angels." 

Perchance you may have stood out in the 
open only just last night and watched them! 
Perchance, too, you murmured softly to your- 
self, as you so often have: 

"Twinkle twinkle, little star, 
How I wonder what you are!" 

But, do you not know? The stars are suns. 
Astronomers tell us that our Sun is a star, and 
that it is not nearly so bright, and by no means 
as large, as many of the stars which shine over 
our heads at night. But they are so far away 
that their splendid light seems to us but a mere 
twinkle. 

The Sun is our nearest star — 93,000,000 miles 
away. If we could fly thirty miles an hour, 



2 WHAT THE STARS ARE 

and should set out for the sun, not pausing for 
rest night or day, we should reach our destina- 
tion in 345 years! Naturally the brightness of 
the Sun's glare, as it sweeps upon us by day, 
shuts out the glimmer of the more distant stars. 
But they are always in the sky, even though 
invisible to the naked eye. If we could stand 
upon one of the bright stars which we see in 
the heavens, and look toward our Sun, we would 
be surprised to find how dim, and insignificant 
it looks. It would appear as a small star, if, 
indeed, we were able to see it at all. 

"To the ancients," says Macpherson, in his 
Romance of Modern Astronomy, "the earth was 
the center of the Universe, fixed and immovable, 
the end and aim of the entire creation. Round 
the Earth revolved the Moon, the Sun, the 
planets, each in its own particular complicated 
pathway, and, farther away, the fixed stars, 
which they believed to be points of light fastened 
to the inside of a sphere. What lay beyond 
was outside the Universe. The whole Universe 
was supposed to be small in extent; its size was 
quite easily grasped by the mind of man. The 
Universe, too* in the opinion of the ancients,, 



WHAT THE STARS ARE 3 

was created purely for the benefit of the Earth's 
inhabitants, the Sun to give light and heat, and 
the Moon to illuminate the nights, while the stars 
were regarded as convenient secondary light- 
givers in the absence of the Moon." 

How much greater is our knowledge to-day! 
We know that the Earth is far from being the 
center of the Universe; it is not even the center 
of the planetary system to which it belongs. 
Indeed, instead of being the largest and most 
important body in the Universe, the earth is 
merely "the second-rate satellite of a second- 
rate star!" Nor are the dimensions of the Uni- 
verse at all within the bounds of man's compre- 
hension. The solar system alone is over 5,000 
millions of miles in diameter. — What mind can 
conceive of this illimitable vastness? — And the 
solar system — that is our Sun with its planets, 
their satellites, and the comets — is a mere speck 
when compared with the greater system of the 
stars. Indeed, we are told that 9,250 solar 
systems of the size of ours could be contained in 
the space which isolates us from: Alpha-Centauri, 
the nearest star. Truly the study of the stars — 
the science of astronomy — is the science of In- 



4 WHAT THE STARS ARE 

finity and Eternity. By means of the telescope 
and the spectroscope, we are led on an immeasur- 
able journey away into boundless space where 
even Time itself is lost. 

In the entire stellar system there are prob- 
ably about 500,000,000 stars. Whether each of 
these stars is surrounded by attendants, like 
those which surround our sun, is impossible to 
determine; but it is altogether probable, and it 
aids us in realizing the extent and magnificence 
of the Universe in which we are situated. Be- 
tween the earth and Alpha- Centauri (invisible 
only in southern latitudes) stretches an immense 
desert of space, twenty five billions of miles 
across. It is hard to grasp an idea of such a 
vast distance. Professor Ball says that it would 
take 300,000 years of ceaseless counting day 
and night even to count that num'ber of miles. 
Again he says that all the cotton yarn ever 
spun in the world, joined in one long thread, 
would not reach to Centauri. Furthermore, he 
tells us that it takes light four years to come from 
this star to the earth. 

But this is not all. When we look at the 
star now we see it as it was four years previously* 



WHAT THE STARS ARE 5 

In fact, if the star were to go out altogether, we 
might still continue to see it twinkling for a 
period of four years longer, because a certain 
amount of light was on its way to us at the 
moment of extinction, and so long as that light 
keeps arriving here, so long shall we see the star 
showing as brightly as ever. When, therefore, 
you look at the thousands of stars in the sky 
to-night, there is not one that you see as it is 
now, but as it was years ago. 

With the aid of our telescopes we can bring 
into view thousands of stars so far distant that 
their light must have been hundreds of years on 
its way to us. When we behold them, we do not 
see them as they are to-day, but as they were 
many, many years ago. Some, in fact, may be 
utterly extinct. 

On the other hand, suppose there were astrono- 
mers living in these distant worlds. If they had 
telescopes powerful enough, they could witness 
events on our own planet — but they would see, 
not our busy life of to-day, but perchance some 
great scenes of the past — the Battle of Water- 
loo, Columbus discovering America, or the Cru- 
sades. Indeed, says one writer, "If we could 



6 WHAT THE STARS ARE 

view our own Earth from mirrors reflected in the 
stars, we might still see Moses crossing the Red 
Sea, or Adam and Eve being expelled from 
Eden!" 

Thus it will be seen that if we had telescopes 
powerful enough to read and understand the 
stars, many of the secrets of the Universe would 
be such no longer. For example, if we could 
view the earth through the successive epochs of 
the past, all the geological problems that now 
puzzle us would be quickly solved. We should 
"be actually able to see those great animals whose 
fossil remains are treasured in our museums 
tramping about over the Earth's surface, splash- 
ing across its swamps, or swimming with broad 
flippers through its oceans." Indeed could we 
but interpret the revelations of starlight, we 
should have mirrored before us a story which 
for majesty, wonder, and sheer unexpectedness 
would stand unrivaled in the whole realm of 
literature. 

At first thought it would seem wholly impos- 
sible to measure the distance of a star from the 
Earth. But astronomers tell us that the 



WHAT THE STARS ARE 7 

principle is no more difficult than those which 
frequently confront the land surveyor. The 
process merely involves taking certain angular 
measurements on the sky, and applying to them 
certain simple theorems well-known to the 
student of trigonometry. Right here is called 
into use a certain high-sounding astronomical 
term — parallax. In plain English the parallax 
of a distant point is the angle made by the cross- 
ing of two lines of vision directed one at each 
side of the object. Knowing this angle, to- 
gether with the length of the base, the problem 
of distance is a simple one. It is not the rule, 
therefore, but its practical application which 
works the difficulty in obtaining star measure- 
ments. Using the diameter of the Earth's orbit, 
186,000,000 miles, as a base line, the astronomer 
records his position and) draws an imaginary 
line to the star he wishes to measure. Then he 
waits six months, while the obliging Earth 
changes his place in space, carrying him with- 
out any effort on his part to the opposite end 
of his base line, when he makes another obser- 
vation. The shift or displacement of the star on 



8 WHAT THE STARS ARE 

the background of the heavens gives him the 
parallax angle which he has been working to 
secure. 

The theory is good, but the trouble is 
that the displacement at best is exceedingly- 
slight — "about equal to the apparent distance 
between the heads of two pins placed an inch 
apart and viewed from a distance of 180 miles I" 
Indeed, in the vast majority of instances, stars 
measured in this way show no apparent displace- 
ment, or at best give such a minute parallactic 
angle that it is impossible to secure trustworthy 
results. Fortunately, however, in this day and 
age we need no longer depend entirely on this 
method for star measurements. The perfection 
of an instrument called the heliometer for mak- 
ing angular measurements on the sky, together 
with the development of star-photography, and 
certain other more recent methods, have reduced 
star measurements to such a degree of accurate 
ease that we now have parallaxes based on the 
millionths of a second of arc. Indeed the far- 
thermost object known in the heavens is a globu- 
lar star-cluster at a distance of 1,260 quadrillion 
miles. Can one imagine anything like this 



WHAT THE STARS ARE 9 

enormous distance away into space? It is more 
than thirteen and one-half trillions times greater 
than the distance to the Sun. If one could em- 
bark on a cannon ball traveling half a mile per 
second, one would be eighty billion years reach- 
ing this goal. Again, a giant would need to 
take 13,300 billion strides as long as the distance 
from the Earth to the Sun to reach this far-off 
cluster. 

From the very beginning of star measure- 
ment it was seen that the term mile conveyed 
little meaning when applied to star distance 
Therefore astronomers invented a new unit, the 
light year, for the distance traversed by light 
in one year. As light travels about 180,000 
miles per second, it will be seen that the light 
year is well fitted by its stupendous magnitude 
for measuring the immense distances of stellar 
space. It also affords the best possible medium 
for our comprehension when used in comparison. 
For example, light crosses the diameter of the 
entire solar system in eight hours: yet it takes 
about four years to come from Alpha-Centauri. 
Light reaches us from 61 Cygni — our first 
star to be measured — at a distance of fifty- 



10 WHAT THE STARS ARE 

three billions of miles away, in about seven years ; 
it comes from Sirius, the most brilliant star in the 
sky, fifty-eight billions of miles distant, in eight 
years. Light is a little over twenty-nine years 
in reaching us from Aldebaran, "the Bull's eye"; 
it takes forty-four years to come from the Pole 
star; and over two hundred years to travel from 
Arcturus, the brightest star in the northern 
constellation of Bootes, the Herdsman. How 
enormous must be this latter star which shines 
so brilliantly from such a vast distance! Comr 
pared with Arcturus, our Sun, great and splen- 
did as he appears, is but a mere dot. Speaking 
of this enormous sun of space, Serviss says: 
"Imagine the earth and other planets constitut- 
ing the solar system removed to Arcturus and 
set revolving round it in orbits of the same forms 
and sizes as those in which they circle about the 
Sun. Poor Mercury! For that little planet it 
would indeed be a jump from the frying pan 
into the fire, because as it rushed to perihelion, 
the point of its orbit nearest the Sun, Mercury 
would plunge more than 2,500,000 miles beneath 
the surface of the giant star. Venus and the 
Earth would melt like snowflakes at the mouth of 



WHAT THE STARS ARE 11 

a furnace. Even far-away Neptune would 
swelter in torrid heat." 

All this but brings us to a fuller realization 
that indeed, "One star differeth from another 
star in glory." For not only are the stars to be 
found at all distances, but they vary in size, 
and frequently their marvelous immensity is 
even more overwhelming than their distance. 
We find it difficult to conceive of a body so 
vast as our Sun. A diameter a hundred times 
that of the Earth means little. Let us set up 
the familiar illustration of a foot-ball and a bird- 
shot side by side: now we have a good compara- 
tive idea of the size of the Sun and the Earth. If 
possible, try to imagine a gigantic orb equal to 
four thousand such suns as ours: this is Capella, 
a brilliant star midway between the Pole star 
and the constellation of Orion, the glory of our 
winter skies. Two other inconceivable orbs are 
Rigel and Betelgeuse, the two brilliant stars 
in Orion. The latter is one of the wonders of 
modern astronomy. It has been estimated as 
forty-three million times larger than our Sun! 
And Antares, a star in the constellation of Scor- 
pion is said to be much larger than Betelguese, 



12 WHAT THE STARS ARE 

More than this it has been averred that however 
startling the size of Antares may prove to be, 
there are other stars whose immensity may even 
surpass it! 

"Infinite as the sands of the sea," thus the 
ancients styled the number of the stars in the 
heavens. To-day we know that this estimate is 
overdrawn, for were the stars in reality so numer- 
ous the whole heavens would be bright with a 
diffused light, and there would be no night. 
Indeed, you may be surprised to know that the 
stars that may be seen with the naked eye, count- 
ing over the whole range of the sky, are no 
more than 5,000 at best, while those which may 
be seen in any one locality will not number 
above 3,000. Thanks to the spectroscope we 
not only know of what the stars are made, but 
we are able to discern that they revolve in orbits 
and are moving through space at a high speed. 
Yet they are so far away from us that they 
seem to be fixed, and so we generally consider 
them, speaking of them as "fixed" stars to dis- 
tinguish them from the planets or "wandering" 
stars. Thus, as one authority points out, "The 
constellation Orion preserves throughout the 



WHAT THE STARS ARE 13 

ages its well-known form. Similarly the Plow 
shines down on us to-day as it did on the king- 
dom of Israel and on the plains of Troy. So 
that for all practical purposes we are correct 
in speaking of the fixed stars. And yet, 
scientifically speaking, we are wrong. The stars 
are no more fixed than are the planets. Indeed, 
many of the stars are moving through space 
with a velocity far greater than the swiftest of 
the planets. . . . For example, 61 Cygni moves 
at the rate of thirty miles per second; while 
the bright star Arcturus has been calculated 
to have a velocity of no less than 376 miles per 
second. . . . But so distant are the stars, so 
deep are they sunk in the depths of space, that 
in the course of hundreds, even thousands of 
years, the casual star-gazer can detect no dif- 
ference in their positions." * 

Whither are all the heavenly bodies fleeing? 
This question troubled astronomers for ages, 
nor has it ever been entirely settled. We do 
know, however, that our own Sun, with his 
system of worlds, is moving along at the rate 
of eleven miles per second toward the constella- 

1 Macpherson, 



14 WHAT THE STARS ARE 

tion of Lyra, aiming apparently for the star 
known as Delta-Lyrse. But, although this voy- 
age has been in progress since the human race 
has been in existence, the eye of man has never 
yet been able to note any resulting displacement 
of the stars unaided. Moreover, it is certain 
that not less than 180,000 years must pass before 
our system, even moving at this impetuous speed, 
could possibly traverse the distance to the point 
now occupied by the nearest star. So that, 
while this mighty voyage through space is im- 
pressive, we have no cause whatever for alarm. 
Another feat of the spectroscope is to show 
us that the stars are not all moving in the same 
direction. For example, the brilliant star Alde- 
baran is speeding away from our system at the 
astonishing rate of thirty miles per second. 
Some stars share " their proper motions with 
others." That is they move along at the same 
rate as some other neighboring star or stars. 
For instance, five of the seven stars which make 
up the familiar constellation of the Big Dipper 
are moving with the same velocity and in the 
same direction, and it is apparent that they form 
one star-system, even though they are separated 



WHAT THE STARS ARE 15 

from one another by billions of mites. Early 
astronomers concerned themselves a great deal 
over whether or not there was a central star 
round which all the other stars and systems 
centered, in the fashion displayed by our solar 
system. A certain German astronomer fixed 
upon the constellation of Perseus as the center 
of the stellar universe; another of his country- 
men believed he had found conclusive evidence 
that the stars all centered around Alcyone, the 
chief star of the Pleiades. Neither of these 
theories ever found general acceptance, and to- 
day it is believed that there could be no one 
sun large and powerful enough to control the 
motions of all the other heavenly bodies. 

Instead, astronomers generally have adopted 
the Milky Way as "the vast highroad to Jove's 
court.' ' Here is assembled an infinite host of 
stars that, no doubt, have come in frorft the wide 
desert of illimitable space. Toward this milk- 
white road countless globular star-clusters and 
nebulas seem to be rushing from either side. 
While other bodies — the mysterious spiral 
nebulas — seem to be fleeing away! It is a 
baffling picture, and one concerning which all 



16 WHAT THE STARS ARE 

sorts of conjectures have been advanced. None 
seems clearer, however, than that voiced by 
Professor Garret P. Serviss, who sees the great 
Milky Way driving through space, "like a flat 
shining raft, built up of hundreds of millions 
of stars — our little Sun being lost among them — 
and drawing in from, either side, and from dis- 
tances of hundreds of quadrillions of miles, 
vast stellar organisms, of a globular shape, on 
which it feeds and grows, while from before it, 
like frightened flocks of strange winged crea- 
tures, hatched in the midst of the mysterious and 
boundless ether, flee the spiral nebulae, speeding 
madly on — on — on." 

Surely a strange, weird, and wondrously 
interesting romance is the story of the stars! 
Suppose that this very night, while we were 
attentively studying the heavens, there should 
suddenly spring into place, in a wide patch of 
blue, a bright and beautiful star! A star which 
no catalogues record, for the reason that it is 
a star which no one has ever seen before! And 
yet such an occurrence would be by no means 
unusual: any well-versed astronomer would be 
able to predict accurately the new arrival's 



WHAT THE STARS ARE 17 

course. For several nights it would grow in 
brilliancy, until perchance it ranked with the 
brightest stars in the heavens; then it would 
begin to wane and die down to the appearance 
of a faint star or perhaps disappear altogether. 
What does it mean? Whence came the brief 
visitor? At first it was supposed that these 
temporary stars, as they are called, rose from 
a violent collision between two heavenly bodies. 
The spectroscope, by analyzing the flame pro- 
duced, not only showed this highly improbable, 
but suggested what is now universally accepted 
as the real solution, that two stars in their jour- 
ney through space happen into a nebulous region, 
and thus flare up by reason of friction — a theory 
that is further supported by the fact that tem- 
porary stars seem, nearly always to be involved 
with a nebulous haze. But the most amazing 
part of it is that this occurrence which we herald 
as the appearance of a new star is, in truth, 
only the message of a huge disaster, a mighty 
conflagration which took place hundreds, per- 
haps thousands of years ago, and has but now 
reached us on the wings of light. 

Many instances of temporary stars are on 



18 WHAT THE STARS ARE 

record, one of the earliest having been seen by 
Hipparchus, the famous Greek astronomer, in 
the year 134 B. C. One of the most notable 
heavenly conflagrations took place in May, 1866, 
when an ordinary telescopic star suddenly 
blazed forth with such intensity that in a few 
hours it increased its brilliance nearly a thou- 
sand fold. Careful spectroscopic study of its 
phenomena showed that the outburst was due 
to an explosion of hydrogen gas, and the inci- 
dent caused no little uneasiness everywhere. 
"What would likely be the result, if a conflagra- 
tion like that which took place on this remote 
sun were at any time to happen to our Sun?" 
queried an Edinburgh astronomer, thus voicing 
the fear of all. "Not only would all the various 
forms of life on Earth be utterly destroyed, but 
on all the members of our solar system there 
would be such a change effected, that if any life 
existed even on the remote Neptune it would 
at once be completely extinguished. Probably 
the life that existed on the whole system of 
worlds that circled round this distant star must 
have been annihilated, and as the heat and light 
of this star increased so very suddenly, there 



WHAT THE STARS ARE 19 

could have been given but short warning to the 
inhabitants of these worlds." 

Temporary stars only blaze up once and then 
die down, but there is another class, called 
variable stars, which are quite as remarkable, 
and have given astronomers even more difficult 
hours to account for their peculiarity. These 
stars get brighter and brighter up to a certain 
point, then wane, only to brighten again, with 
a regularity that can be reckoned with the utmost 
accuracy. Some go through their course in 
three days, others take much longer, the max- 
imum being 600 days. What is the explana- 
tion? A simple enough one, truly! Either 
these stars have a smaller dark companion which 
gets around into position every so often and shuts 
off the light, or they have a bright double, 
which in certain lines increases or decreases the 
brilliancy. 

Still not half of the wonders of the stars have 
been told ! We shall see as these pages progress 
how man has ever turned to the heavens to un- 
ravel the answers to much of Nature's puzzling 
phenomena. In the stars he has not only 
deciphered the past of our own world, but he 



20 WHAT THE STARS ARE 

has in a great measure been able to trace its 
future. For just as the buds, blossoms, and 
seeds of the plants in our gardens record the 
life history of their species, so do the different 
stages of star and planet life, from the various 
masses of luminous nebula to the dead worlds 
and dark stars, record the past and future of 
our own dwelling-place, the Earth. We are, as 
Kepler, one of the early astronomers, long ago 
pointed out, permitted in a measure to see the 
marvelously wonderful method by which the 
Creator called into being the magnificent 
Universe in which we live; to think as it were 
the thoughts of God after Him! We realize, 
too, as we ponder, a new depth and beauty in 
the words of the prophet Isaiah: "For My 
thoughts are not your thoughts, neither are your 
ways My ways, saith the Lord: for as the 
heavens are higher than the earth, so are My 
ways higher than your ways and My thoughts 
than your thoughts.' 9 



II 

THE SUN, TO US THE GREATEST STAR OF ALL 

The early peoples of the world worshiped 
the Sun as the Lord of Day, the Fountain of 
Light, and the Bringer of all things good. But 
they were at a loss to account for him: 

Whence are thy beams, O Sun, thy everlasting light? 

Thou comest forth in thy awful beauty; the stars hide 
themselves in the sky; the moon, cold and pale, sinks 
in the western wave; but thou thyself movest alone. 

— Ossian 

And whither? No one knew that the Earth 
was round, when Ossian wrote. They thought 
it was a great flat plain, extending in every 
direction. It seemed that the Sun daily trav- 
ersed the sky only to plunge into the western sea ! 
Indeed, there were those who fancied they 
heard the dreadful hissing noise when the glow- 
ing, red-hot orb dropped into the Atlantic! But 
here was the difficulty: how did it get around 

to the East, and rise fresh and hot as ever the 

21 



22 THE SUN 

next morning? Surely the plunge into the water 
should have quenched it! Some said that we 
had an entirely new sun each morning. The 
business of making the suns was supposed to 
be in the hands of the gods; all day and all 
night they worked with Titanic energy, and 
each succeeding morning saw a new orb launched 
forth on its journey. 

This, however, seemed a waste of suns, and 
presently a new theory was evolved: Vulcan, 
the God of Labor, had the matter in charge. 
When the Sun dropped into the sea in the West, 
it was his business to rescue it and row it around 
the northern route to the East. Some of those 
who sat up all night to watch for indications 
of the progress of this journey, fancied they 
could trace the light of the glorious cargo along 
the northern horizon. Besides how else could 
one account for the long midsummer twilight? 
A tedious night's voyage poor old Vulcan had 
of it! Nor was there even a moment's respite. 
As soon as he reached the East, he must launch 
the Sun with terrific energy, so that it would 
not flag nor falter all the day, and then paddle 
back the way he had come, with unceasing in- 



THE SUN 23 

dustry, so as to be ready to catch the Sun in 
the evening, and be off again on his unending 
task! 

Time has settled this problem, as well as 
that other great phenomenon, the change of 
seasons, which was even harder for the ancients 
to solve. Gradually people have come to under- 
stand these "miracles," and to take them as 
a matter of course. No longer do we feel awed 
when darkness settles down, and we have abso- 
lutely no fear concerning the return of day; 
neither are we troubled over the unending 
struggle between summer and winter. Like- 
wise, too, we accept all the other beneficences 
of the Sun. But it is well for us to pause now 
and consider that without the Sun, life on the 
Earth would be impossible. To him we owe 
light, heat, power, food, water, in short, every- 
thing that we have, even the Earth itself. Per- 
haps we shall understand this latter statement 
better by illustration: 

Draw down the shades, light the candles^ 
and let us consider it while we have tea and 
muffins in the cozy radiance beside the fire- 
place. How cheerful the fire's ruddy glow! 



24 THE SUN 

Do you know that it is stored-up sunshine? 
"Why," you exclaim, "the fire is only coal." 
Yes, but what is coal? It is the fossil remains 
of giant trees, huge ferns, and hixuriant grasses 
and mosses which once grew by reason of the 
warm sunshine and soil-water. These muffins, 
too, were made from wheat grown by the Sun. 
Even the very power that ground the flour came 
from the Sun. 

No matter whether ground in a mill turned 
by wind or by steam, the Sun did the work. For 
the Sun furnishes both wind and water. All 
the air currents on our earth are due to the 
Sun in this wise : great tracts of land are warmed 
by the pleasant sunbeams. The air, in turn, 
is heated and rushes upward, while the cooler 
air slips in to fill its place. To do this, the 
air, of course, moves across the country. It 
is wind. And it is the Sun that has started 
it. All the water we use comes from the clouds, 
either as snow or rain. Even the water we have 
here in our teapot was floating far overhead, 
only a little while ago. Before that, perchance, 
it was just some tiny drops of water in the 
ocean. The Sun poured down his warm beams 



THE SUN 25 

upon them, the drops turned to vapor, and 
climbed into the sky, there to unite in the cooler 
atmosphere with other rising drops and thus 
form a cloud, which floated our way. By and 
by the wind came rushing along, the vapor 
cooled still more and changed back to drops 
again, falling as rain, until 1 presently the little 
cloud wept itself away. The drops seeped 
down deep into the soil, and at length found 
their way into the underground vein which 
empties into our well. Our tea is a product of 
sunshine. It came over sea in a ship built and 
run by sunshine. Look anywhere you may 
about the room: you can see nothing which does 
not owe its all to sunshine. Sunshine even grew 
and bleached this lovely white lunch cloth, and 
gave the pretty colors to your dresses. 

Countless, indeed, are the marvels connected 
with the Sun, but of them all none is more 
astounding than its vast distance from us and 
its enormous size. Astronomers have determined 
that 93,000,000 miles of space stretches between 
us and the Lord of Day. But do you have any 
idea of this vast distance? Suppose you try 
to count 93,000,000. Professor Ball says the 



26 THE SUN 

best way will be to let the clock do this: "How 
long will the clock have to tick before it has 
made as many ticks as there are miles between 
the Earth and the Sun? Every minute the 
clock, of course, makes sixty ticks, and in twenty- 
four hours the total number will reach 86,400. 
By dividing this into 93,000,000 you will find 
that more than 1,076 days, or nearly three years, 
will be required for the clock to perform the 
task." 

Again, here is another illustration: It is 
nearly 25,000 miles round the world. The 
journey can be accomplished in sixty days. 
Traveling at this rate, one man' might make 
4,000 journeys around the world while another 
was covering the same distance between the 
Earth and the Sun. No man, of course, could 
accomplish this feat, even if such a journey were 
possible. He would be 600 years old when he 
reached his destination, even if he set out when 
a mere babe. As another instance, suppose 
that a train had started for the Sun, dur- 
ing the time of Cromwell, traveling at the rate 
of forty miles an hour, and stopping neither 
day nor night, it would not yet have reached its 



THE SUN 27 

destination. It would require 265 years to com- 
plete the journey, and no man who started on 
the train could hope to be in at the finish. The 
journey must be ended by his great-great grand- 
children. 

No less amazing than the Sun's distance is 
his size. Approximately his diameter is 866,- 
000 miles. This means that 109 globes the size 
of our Earth, set side by side across the face of 
the Sun, would not quite cover it. Again, com- 
paring the vohime of the Sun with that of the 
Earth, Professor Gregory gives the following 
illustration: "If we had a contract to build 
up this stupendous bulk, and were to deliver 
a load of the same size as the Earth every hour, 
the order could not be completed working night 
and day for 150 years." 

Though the Sun is vastly greater than the 
Earth in volume, it weighs only 330,000 times 
as much. Thus the density of the Earth is about 
four times that of the Sun. The reason of this 
is that the Earth is a solid globe, while the Sun 
is a great glowing ball of incandescent gas. Nor 
is the force of gravity at the Sun's surface so 
great as his immense mass would seem to indi- 



28 THE SUN 

cate : it is only twenty-seven and two-thirds times 
as great as gravity at the surface of the Earth. 
A body would fall vertically 444 feet in tfhe first 
second. An athlete attempting stunts on the 
Sun would find his movements hampered by a 
bodily weight of 4,000 pounds. His running 
high jump, if possible at all, would not be over 
three inches. On the Sun, the pendulum of an 
ordinary clock would swing so rapidly that its 
movements could scarcely be counted. 

The Sun is so constantly before us that we 
do not often stop to consider the immense 
amount of energy it is pouring forth every 
second. Astronomers have determined that the 
Sun is immensely hotter than a powerful electric 
arc-light which melts all known substances, and 
scientists have puzzled not a little to account for 
the work which this heat does in the vast regions 
of space; for only the two-billionth part of it 
reaches our Earth and is used to support the life 
of creatures here. On its surface the solar heat 
has been estimated at 18,000° Fahrenheit. How 
shall we realize this enormous heat? From even 
one square meter of this glowing surface enough 
heat is generated to supply 100,000 horse-power, 



THE SUN 29 

continuously night and day. Further than this, 
Professor Young says: "If we could build up 
a solid column of ice from the Earth to the Sun 
two miles and a quarter in diameter, spanning 
the inconceivable abyss of 93,000,000 miles, and 
if the Sun should concentrate his power upon it, 
it would dissolve and melt, not in an hour, not in 
a minute, but in a single second ; one swing of the 
pendulum and it would be water, seven more and 
it would be dissipated in vapor." Were the 
Sun as near to us as the Moon, his powerful rays 
would not only quickly turn all the ocean to 
vapor, but the solid Earth itself would be speed- 
ily melted. 

How do astronomers know all this? By 
experiments with burning-glasses, mirrors, and 
arc-lights. The Sun's heat is determined by 
opposing it to an electric arc and measuring the 
heat which both produce at different distances. 
You may perhaps have started a camp-fire by 
means of the Sun's rays through a burning-glass ; 
or perchance you may have seen a cannon cov- 
ered by a burning glass in such a way that the 
Sun's rays touched it off at the noon hour. 
Sometimes one discovers black spots on leaves 



30 THE SUN 

that have been caused by the drops of dew act- 
ing as little burning-glasses and concentrating 
the Sun's rays. It is an interesting experiment 
to make a lens out of ice, and burn a piece of 
paper by means of Sun rays which have passed 
through such a cold body. A mirror from an 
old automobile reflector is ideal for concentrat- 
ing the Sun's rays, as its curved surface brings 
the beams to a direct focus. If the mirror is 
large enough an iron nail will burn like a match 
in the heat generated. 

From experiments with large mirrors, we 
know that the heat of the Sun must be capable 
of melting all known metals, and glass and 
porcelain ; for the Sun must be even hotter than 
the focus of the largest mirror we can construct, 
since a wall exposed to a blazing fire cannot be 
hotter than the fire itself. "With the Sun in the 
zenith," says Professor Todd, "his heat is power- 
ful enough to melt annually a layer of ice on 
the earth nearly 200 feet in thickness." 

The time is coming when the world's supply 
of bottled sunshine — wood and coal — will have 
disappeared; so that, within a century or two, 
new ways of furnishing heat and power must 



THE SUN 31 

be devised, or the human race will perish of cold 
and hunger. Fortunately electricity and wind- 
power are at hand, but greater than either of 
these two sources is the unlimited might of the 
sea tides, which men have sought in vain to 
harness; and the direct heat of the Sun itself. 
Already solar motors have been invented — such 
as those by John Ericsson, the great Swedish 
engineer who built the Monitor, by Mouchot, 
Schuman, and others; the principal features to 
make them a success — cheapness and prac- 
ticality — have not, however, been arrived at. 
Perhaps the key to these may be in the hands 
of some one who reads these words! Certain 
it is that the dependable solar motor is bound to 
come. Think what such a source of cheap 
power will do. Above all, it will make valuable 
countless acres of desert land, providing homes 
for thousands on profitable irrigated tracts. 
Any place in the tropics where the sun shines 
practically speaking throughout the year, and 
where ordinary fuel is very expensive, offers 
excellent opportunity for the solar motor. A 
small solar plant on the roof of the modern 
apartment house will not only light and heat 



32 THE SUN 

it at the least possible cost, but it will cook the 
meals of the inmates, run the sewing-machine 
and the vacuum cleaner, and in short furnish 
power wherever power is needed. 

One of the great mysteries in regard to the 
Sun's heat is its constancy. It shines to-day 
just as intensely as it did as far back as man 
has any record. How is this enormous 
heat kept up ? Certainly it is not by the combus- 
tion of carbon. Had the Sun been composed 
of coal it must have burned out in less than five 
thousand years. And apparently the sun is 
in his prime! Scientists have decided that the 
only real plausible theory for the Sun's heat is 
that he is contracting upon himself. If this be 
true, he must have been vastly larger in the 
remote past, just as in the far distant future 
he will be very much reduced in size. It has 
been estimated that the burning of gases in a con- 
traction of his diameter of six miles per century 
would fully account for his present heat. At 
this rate it has been calculated that the Sun will 
shrink to one-half of its present diameter in five 
million years. While certain types of life would 
disappear, enough heat and light would still be 



THE SUN 33 

emitted for another five million years. But, 
after that period the glacial epoch would again 
dawn, and presently the Sun and his retinue 
would swing silently through space as cold, inert 
lumps of matter. That there are many types of 
such dead suns in the heavens is a fact well- 
known to astronomers. 

No less remarkable than the heat of the Sun 
is his brightness. The intensity of sunlight, as 
it is called, has been calculated as 190,000 times 
that of a candle, 146 times that of a calcium 
light, and nearly four times brighter than the 
brightest electric arc-light; 600,000 full moons 
would be needed to equal the light of the Sun. 
Absorption by the Sun's own atmosphere not 
only reduces the amount of light which we 
receive, but changes its character. According 
to Langley, were it not for its atmosphere, the 
Sun would shine two or three times brighter 
than it now does, and with the bluish color of 
the arc-light. 

Of course no one can look directly at the Sun, 
but by observing him with the aid of a tel- 
escope, or even through a darkened glass, we 
behold first a disc of yellow light — the 



34 THE SUN 

photosphere, astronomers term it. Looking at 
this carefulry, we may note that the brilliant 
surface is marked with dark spots. These are 
called sun-spots. But they are not permanent 
features of the Sun, like the mountains and 
craters are of the Moon. They are only tem- 
porary markings, here to-day perhaps and gone 
to-morrow. Sometimes the spots close up within 
a few minutes and fresh ones open elsewhere. 
Again the whole surface seemes mottled over 
in a curious way. 

What does it all mean? Galileo and Scheiner, 
the astronomers who first discovered this 
phenomenon, could scarcely credit their senses. 
Surely the sun was too dazzlingly perfect to 
show defects, such as the sunspots seemed to 
be! At length, however, it was determined 
that the photosphere was merely the brilliant 
envelope or light-sphere of the sun, and that the 
dark spots were in truth great rents or holes in 
the glowing envelope, through which the core of 
the Sun was seen. Shortly, by means of the 
sunspots, astronomers were assured that the 
Sun, like the Earth, rotates on its axis. But 
"the day" of the Sun is twenty-five and one- 



#>• 




♦ 




THE SUN 35 

quarter times longer than that of our planet. 
Another interesting fact is that the sunspots in- 
crease and decrease about every eleven years. 
Incredible as it may seem, the discovery of this 
solar cycle, as the increase and decrease of the 
sunspots is called, was made by a mere amateur 
in astronomy, whose only instrument was a hand 
telescope! In 1826, a German apothecary 
named Schwabe, who had been interesting him- 
self in the heavens, commenced to count the num- 
ber of spots on the sun as seen from day to day. 
After about twenty years had passed, he began 
to feel sure that there was a periodic increase and 
decrease of the sunspots, and by 1851 he had 
triumphantly proved the existence of the solar 
cycle — an important fact that had escaped the 
observation of all the noted astronomers. To- 
day it is known that when the sunspots are 
most numerous the aurora borealis is the most 
frequent and vivid ; at this time, too, the presence 
of magnetic disturbances is noted in the fluctua- 
tions of the delicately mounted magnetic needles 
at Greenwich and in various other observatories. 
The largest sunspot on record covered about one 
thirty-fifth of the whole sun. This occurred in 



36 THE SUN 

1858. In February, 1892, another huge spot 
appeared, some 92,000 miles in length and 62, 
000 miles wide. Closely connected with this 
huge gap in the photosphere were a number of 
smaller spots, in all making a rent that seventy 
bodies of the diameter of our Earth would have, 
been required to patch. 

Besides the sunspots, the telescope reveals an- 
other decidedly interesting feature on the bright 
surface of the Sun. This is the appearance of 
brighter streaks or ridges, called the faculce, and 
wholly as irresponsible and notionate as the sun- 
spots whose neighborhood they seem to frequent. 
Often it is impossible to sketch their form, so 
quickly do they appear and disappear. Some 
astronomers believe them to be elevated peaks of 
luminous matter extending thousands of miles 
above the gaseous plain. Some are evidently 
composed of clouds of incandescent calcium, an 
element which exists freely in the Sun. As a 
rule, sunspots are usually confined to the two 
zones above and below the solar equator, while 
the f aculse are often found well distributed over 
the Sun's surface, excepting in the "polar" 
regions. 



THE SUN 37 

For a large part of our knowledge of the Sun 
we have to thank the Moon. Occasionally this 
beneficent body gets between us and the Sun, 
producing an eclipse. Then, of course, we do 
not see the Sun, but we see something for the 
moment infinitely more interesting and beau- 
tiful. This is the wondrous spectacle of the 
corona and the prominences. The corona is the 
marvel of the astronomical world. Unfortun- 
ately it can be seen clearly only about seventy 
times in a century, though there is no doubt but 
that it is a regular part of the Sun — the 
third and final solar envelope, a halo glowing 
with a soft radiant silvery light. "Its shape," 
says Macpherson, "varies in sympathy with the 
eleven-year period, and it seems closely connected 
with electricity and magnetism. It streams out 
from the sun for millions of miles, becoming 
more and more rarified until it gradually fades 
into the ether of space." 

In spite of its infrequency, various pho- 
tographs of the corona have been taken. For 
it is possible for astronomers to figure when 
eclipses are due, the regions of their greatest 
visibility, and the length of their duration. 



38 THE SUN 

These dates are regularly published in the 
Nautical Almanacs, used by the English, 
French, German, and American governments, 
and naturally, at each occurrence, even though 
they must journey half-way around the world, 
representatives from every observatory are on 
hand, with a very definite idea of just what they 
want to accomplish in the few seconds, or 
perhaps moments, of the exhibition. Very 
carefully, you may be sure, are all the details 
rehearsed beforehand, time and again, that there 
may be the most accurate observation. In 1955 
(Luzon) and 1973 (Sahara) will be two great 
total eclipses of seven and one-half minutes' 
duration, the longest for a thousand years. 

The prominences, or red flames, which were 
first to be seen only at eclipse dates, are now, 
happily, to be observed almost any time. But 
they are not to be seen through even the most 
powerful of telescopes. You must call into 
service one of those ingenious oft-mentioned 
contrivances called a spectroscope — an instru- 
ment which is no more nor less than a special 
kind of a glass prism. By this means the 
prominences are shown to be tongues of glowing 



THE SUN 39 

fire shot forth with tremendous power from the 
chromosphere — an irregular rose-tinted fringe, 
varying from five to ten thousand miles in width, 
which completely encircles the sun, forming its 
second envelope. Many of these prominences 
are of enormous height, ranging from an 
average of 25,000 miles — about the circum- 
ference of the Earth — to 350,000 miles, nearly 
half of the Sun's diameter. Like the sunspots, 
the prominences increase and decrease every 
eleven years. Their variety of color shows them 
to be the gaseous vapor of various well-known 
metals, chiefly calcium (fiery-red) and iron (dark 
colored). Dairy photographs of the Sun's 
prominences are taken in various observatories, 
but especially is this a feature at the Carnegie 
Solar Observatory in California. Two forms of 
prominences are known: brilliant eruptive jets 
and cloud-like wide-spreading shapes. 

Few people who look up at the arc-lights 
which illuminate most of our city streets give 
any thought to how interesting and mysterious 
that light is. We know that it is the nearest 
thing possible to direct sunlight; in truth the 
arc-light is really the Sun's own imitation of 



40 THE SUN 

himself. Thousands of years ago the Sun's 
energy was packed deep in the coal mines of the 
earth. To-day man has unearthed this treasure 
and turned it into carbon rods, which have again 
been led to produce the light and heat which the 
Sun stored up eons ago. By the aid of the Sun's 
own bottled energy, miraculous as it may seem, 
we have measured his heat. Through the me- 
dium of the multi-useful spectroscope we have 
watched various substances burn in the arc until 
their gaseous color is familiar on sight. By 
applying this same knowledge to the colors 
observed in the Sun's spectrum, we have been 
able to determine of what the Sun is made. 
So far about forty elements are known to exist 
in the Sun. Strangely enough, too, some 
elements were known in the day's bright orb 
long before they were found on our sphere: 
helium and coronium are two of these. Iron, 
hydrogen, calcium, nickel, and sodium are the 
most abundant of the Sun's elements. 

Of what lies below the Sun's photosphere, in 
the center of his mighty orb, we can form no 
conception. According to one astronomer, "The 



THE SUN 41 

pressure within the Sun is equally unconceivable. 
A cannon ball weighing 100 pounds on earth 
would weigh 2,700 pounds on the Sun. Thus 
a mighty conflict goes on unceasingly between 
imprisoned and expanding gases and vapors 
struggling to burst out, and massive pressures 
holding them down." 

This, then, is our Sun, the center of the solar 
system, the great Fountain of Light, to which we 
on Earth owe all that we have. Besides our 
Earth there are seven planets of considerable 
size, and a whole host of insignificant little ones 
which depend upon the Sun. They all revolve 
about him, and derive their light and heat from 
his beams. In a good many ways these planets 
resemble the Earth. One of them, Venus, is 
about the same size. Mercury and Mars are 
much smaller, but Jupiter, Saturn, Uranus, and 
Neptune are a great deal larger. The nearest 
of these is millions of miles away, and naturally 
but little is known concerning them, though 
people have known of their existence for ages. 
The ancients named the days of the week from 
these seven celestial bodies. 



42 THE SUN 

You will perhaps like to make a drawing of 
our planetary system, in order to give yourself 
an idea of how it appears. 

In order to draw the inner part of the solar 
system to scale, take a piece of blank paper at 
least ten inches square. In the center set up one 
leg of a drawing compass, open the other leg one 
inch, and describe a circle. The central dot, 
which can be enlarged is, of course, the Sun. 
The first orbit thus described is that of Mercury, 
and can be so marked, with "88 days" set down 
for the year, or time to complete the circle. The 
compass should next be opened one and three- 
quarters inches, from the center, and this circle 
will represent the orbit of Venus, 225 days. The 
third circle with a radius of two and one-half 
inches is that of our own Earth, 365 days. The 
fourth circle, with a radius of four inches, is 
Mars, 687 days. This completes the inner solar 
system. A very much larger piece of paper 
would be required to describe the orbits of the 
four outer planets. 

Mercury is 37,000,000 miles from the Sun. 
The Earth is 93,000,000 miles. The great 
planets Jupiter, Saturn and Uranus are much 



THE SUN 43 

farther. Jupiter takes twelve years to go 
around the Sun, Saturn twenty-nine and one- 
half years; Uranus eighty- four years; and 
Neptune, one hundred and sixty-five years. 
Jupiter, the largest of the planets, is twelve hun- 
dred times larger than the Earth. Of course 
these planets are so far away from the Sun that 
they get but little benefit from its light and heat. 
But, the gloom of their situation seems to mat- 
ter but little, for it is highly improbable that 
any of these bodies can be inhabitated. We 
shall have more to say of these planets later. 

4 'The most magnificent work of the Al- 
mighty," thus Schiaparelli defines our Sun, and 
so far as we on the Earth are concerned this is 
absolutely true. Indeed, as we view him in the 
light of all his marvelous greatness, we feel that 
the simple-minded ancients were not far wrong 
in bowing before him. "Surely," says Proctor, 
"if there is any object which men can properly 
take as an emblem of the power and goodness of 
Almighty God, it is the Sun." 



Ill 

MOTHER EARTH, A CHIP FROM THE 
SUN-STAR 

Our Earth, which the ancients thought held 
such an important position in the Universe, has 
now been proven only "a tiny grain of sand in the 
ocean of Infinity." But even so, it still remains 
the spot of the utmost interest to us, and no part 
of astronomy is more fascinating than that 
branch which answers the query, What is the 
Earth? 

In its earliest stage, the Earth was probably 
whirled like a chip from the great mass of star 
stuff of which the Sun was being made. It was 
merely a chaotic nebula of gaseous formation, 
"without form and void," as the writer of the 
Book of Genesis sets forth. Then, "God said, 
'Let there be light'; and there was light." But 
this light did not come from the Sun, says 
science; in its early days the Earth was self- 
luminous, light came from the slow contraction 

of the nebulous mass. By and by, as the heated 

44 



MOTHER EARTH 45 

mass went on whirling, keeping always in a 
certain path or orbit around the Sun, it slowed 
down a bit and began to cool off and a crust 
formed over its liquid surface, just as ice forms 
when water freezes. Then some of the gases 
formed clouds, and these were later cooled and 
condensed into water, which settled back in the 
hardened shallows and basins, made by the still 
cooling mass, to form seas and rivers. Others 
of the gases became air, and so, after some 
millions of years, the earth began to be a fit 
place for certain forms of life. But it was 
excessively moist yet, and the light was only 
the semi-twilight of deep shade, for the dense 
cloud masses shut off all the rays from the Sun, 
and the light and warmth were still supplied by 
the heated Earth. Ferns and plants of like 
nature sprang up and grew to the height of trees, 
covering the land with luxuriant vegetation. 
And still the contraction and vaporization went 
on over an Earth which was continuous and 
equal in climate everywhere. Not yet had the 
seasons begun; no outer Universe was visible. 
And now God said: "Let there be lights in 
the firmament of the heaven to divide the day 



46 MOTHER EARTH 

from the night; and let them be for signs, and 
for seasons, and for days, and years. And let 
them be for lights in the firmament of the 
heavens, to give light upon the earth; and it 
was so." For now the heavy clouds of vapor 
lifted, the skies cleared and the Sun shone in, 
bringing with him a rich heritage of beneficence. 
Now a new race of plants and. animals came 
into being; the earth blossomed with loveliness, 
and the real history of the world began. 

Almost in the beginning, too, men began to 
question one another. What is the Earth? 
And as we have seen, for long they fancied it 
one vast illimitable plain. Gradually, however, 
it was borne in upon them that the Earth was a 
great ball or sphere. Then came another baf- 
fling query; "If the Earth is a sphere, how is 
it supported in space?" The sky, they sup- 
posed, was a vast hollow sphere, or rim, above 
which dwelt the gods. Might there not be 
another rim below the Earth on which great 
pillars were placed to hold it in position? Some 
nations pictured a giant man who held the Earth 
on his shoulders; others fancied it upheld by 
various mythical animals of enormous stature. 



MOTHER EARTH 47 

"Some support, in the minds of the ancients, 
was absolutely necessary," says Macpherson. 
"The author of the Book of Job, however, had 
grasped the truth, for, writing of the power of 
the Creator, he says, 'He hangeth the Earth 
upon nothing.' ' This we now know to be liter- 
ally true. 

, Aristotle taught that the Earth was a globe 
suspended in space. It was, too, the center of 
the Universe, around which the Sun, Moon, and 
stars revolved. But presently a new problem 
arose to complicate matters. Attentive observ- 
ers of the heavens now began to be aware of 
five bright stars which seemed to move in an 
irregular manner round the heavens, keeping 
close to the path which they fancied the Sun 
followed. However, there was good reason to 
suspect that these objects were not stars, and 
shortly the Greeks named them planets, this 
being their term for "wanderers." Each one of 
these planets seemed different from the others. 
One, the brightest of all, shone with such a soft, 
gentle light that they named it Venus after their 
goddess of love. Moreover they noticed that 
Venus never moved far from the Sun, and that 



48 MOTHER EARTH 

they never saw it on a really dark sky. And 
presently they ascertained that Venus was 
sometimes visible as evening star, and again at 
another season of the year as morning star. 
Another planet, "the sparkling one," kept even 
closer to the Sun than Venus, and so they called 
it Mercury, the "messenger of the gods." An- 
other of the planets, "the golden one," they 
called Jupiter, after their own marvelous deity, 
because it seemed mightier than the others, and 
instead of keeping close to the Sun, swept 
majestically round the entire heavens. One of 
a fiery color, which waxed exceedingly bright, 
then waned, they christened Mars, after their 
god of war. And last of all, and fainter than 
any, a dull yellowish, slow-moving planet, which 
crept around the heavens only once in thirty 
years, was called Saturn, after their god of time. 
But how were the paths of these planets to be 
explained? 

Such a complicated theory as presently arose! 
to the effect that the Sun, Moon and planets 
moved in circles, and that the center of these 
circles revolved round the Earth in larger 
circles. It was fostered by Ptolemy, the 



MOTHER EARTH 49 

Egyptian astronomer, and for over 1,400 years 
it held sway. Nobody rightly understood it, 
but they had no better solution to offer. The 
theory of the spheres was an astronomical 
mystery too stupendous for any clear explana- 
tion. But at length rose one, Nicolaus 
Copernicus, who did not believe even what 
little he understood of the spherical theory. 
Nature always did things in the simplest, easiest 
manner possible, he argued, and surely there 
was a plain explanation for the system of the 
Universe. 

Copernicus was only nineteen when he began 
to study the subject. He was brave enough to 
do his own thinking and to strike out in paths 
for himself, but he did not dare to publish the 
theory which he presently envolved — that the 
Sun was the center of the Universe, and that 
the Earth and the planets revolved around it, 
while the Moon revolved around the Earth. 
Surely no simpler accounting could be had, and 
the few great men of science who heard the 
Copernican theory longed to accept it. They 
felt perfectly assured of its truth. But those 
were* days of bitter prejudice. The Roman 



50 MOTHER EARTH 

Catholic church had adopted Ptolemy's version; 
any other would be declared impious. Coper- 
nicus was an old man, seventy years of age, and 
on his death-bed, when his book came out 
proclaiming his solar theory. Bruno was 
burned alive for at once adopting it. Galileo 
and Kepler, the foremost astronomers, ran a 
gamut of persecutions,- but the two bravely 
threw their whole souls into the effort to prove 
the questioned points which Copernicus had 
left. Shortly, then, the fact was established 
beyond a doubt that the Earth was merely a 
planet, a member of the Sun's great system of 
worlds. 

But this theory only presented another prob- 
lem. If the Earth was whirling around the Sun 
at the terrific speed of eighteen miles per second, 
as was claimed, and was also turning on its 
own axis once in twenty-four hours, how could 
objects stay on the Earth? How was it that 
the people did not fall off? Moreover, if we 
were rushing along at the great rate of over 
1,000 miles per hour, wJiy were we not conscious 
of motion? 

It was Sir Isaac Newton who answered these 



MOTHER EARTH 51 

queries, in 1680. Most of our readers know the 
story of the falling apple which disclosed to 
his receptive mind the famous law of gravitation. 
By this law the Earth attracts everything to- 
ward its surface. We could not hurl ourselves 
off into space even if we ardently desired to do so. 
Mother Earth holds us by her power of attrac- 
tion. Similarly this same law of gravitation 
keeps the Moon in its monthly orbit round the 
Earth, and prevents it from shooting off into 
space; also by this same principle the Earth and 
the other planets are kept in their path around 
the Sun. Rut how is it that the Moon is not 
drawn to the Earth, and the planets themselves 
pulled into the Sun and destroyed forever? 
What keeps them following accurate ellipses 
year after year? 

Newton showed that this was due to certain 
other laws of gravitation and motion. For 
instance, the Earth attracts the Moon, and the 
Moon attracts the Earth; but the Earth is so 
much larger than the Moon that she overcomes 
by mere size and forces the Moon into becom- 
ing a satellite. Again, when a body is once 
set in motion and is not acted upon by any force, 



52 MOTHER EARTH 

it will move forward in a straight line, with un- 
changing speed, forever. Thus, the Moon in its 
journey around the Earth, and the planets in 
their course about the Sun, are each affected 
by the greater attraction of the larger body, but 
their own tendency to move in a straight line 
keeps them ever struggling outward. Hence, 
all the heavenly bodies in our solar system keep 
moving in an ellipse, or flattened circle, around 
and around their own great center of attraction. 
Astronomers call the motion of a planet on its 
axis the turning-motion, and its motion around 
the Sun the flying-motion. The reason we do 
not realize the enormous speed at which we are 
traveling, as the Earth rushes around its annual 
orbit of over 600,000,000 miles, is because the 
world is all traveling together, and with such 
ease and freedom from jolt that the motion is 
not noticed. 

In swinging around its appointed orbit, the 
Earth does not stand up straight, but its axis 
points to the north star, causing what is known 
as the inclination of the Earth's aocis, and this 
inclination and the motions of the Earth are 
the talismans which account for certain of the 



MOTHER EARTH 53 

mysteries which puzzled the ancients — day and 
night, the seasons, twilight, the midnight sun, 
and the long polar night. The first of these 
phenomena, day and night, is caused by the 
Earth turning on its axis every twenty-four 
hours; thus the light of the sun strikes one-half 
of its surface at a time, making day on that 
side, while the other side, which is in shadow, 
has night. Owing to the fact that the Earth 
is surrounded by a great rim of atmosphere, 
daylight does not disappear the moment the Sun 
"sets," that is goes below the horizon; for his 
rays still strike the upper regions of the at- 
mosphere, and thus we have a twilight gradually 
deepening into evening-tide and on to the total 
darkening of the sky. If the Earth stood 
straight, it is easy to see that the days and nights 
all over the world would be of the same 
length, — twelve hours each. Instead, the in- 
clination of its axis is twenty-three and one- 
half degrees from the perpendicular. While at 
the poles we have one day and one night each 
six months in length. 

For a few days at the summer solstice, the 
wondrous phenomenon of the Midnight Sun 



54 MOTHER EARTH 

attracts many visitors to the northern parts of 
Norway, Russia, and Sweden. 

It is hard to set down in cold print a picture of 
this glorious spectacle. The radiance of the Sun 
varies in intensity at different hours of the day, 
and on different days, depending upon the mois- 
ture or clarity of the atmosphere, presence of 
clouds, and other factors. One day it will be as 
red as orange, and so dull in radiance it can be 
beheld with the naked eye. At another time it 
burns with the vivid glow of live flame. Again 
there are days at a time when it has a bluish- 
white appearance, almost like the Moon. 

But, the most curious effect of all is the motion 
itself. It does not "rise" or "set" as is apparent 
with us of southern climes. When one nears the 
North Pole there is no East or West or North. 
Every direction in which we look is due south. 
The Sun, therefore, apparently moves round and 
round us in a gigantic circle roughly parallel to 
the horizon. Gradually it descends in a slow 
spiral until it grazes the horizon, like a huge 
cartwheel turning constantly to hem us about. 
Next the cartwheel is cut in half — then only the 
upper segment shows. This disappears, and 



MOTHER EARTH 55 

after a period of twilight, the long Arctic night 
sets in. The return of spring is just the reverse 
of this phenomenon — first the twilight, then a 
faint rim of light crawling round and round the 
edge of the landscape, making complete circles, 
until finally the orb of day ascends his throne 
again. 

The rotation of the Earth on its axis furnishes 
a natural unit for the measurement of time. 
Two days are recognized: the sidereal day and 
the mean solar day. The first is the "day" 
used by astronomers, and is absolutely exact. 
It is the time required for the rotation of the 
Earth's axis as measured by the stars. It is 
calculated by choosing some particular star — 
Beta Cassiopeia, the right "pointer" at the top 
of the letter W formed by the constellation of 
Cassiopeia — is the "Greenwich of the sky" — 
and counting the exact time required for the 
star to move from the meridian round to the 
meridian again. But only an astronomer can 
manage the "juggling" necessary to keep "day- 
light" time by the sidereal clock. The reason 
is that, because of the motion of the Earth, the 
Sun appears to come to the meridian four 



56 MOTHER EARTH 

minutes later each day by sidereal time. This 
means that the day measured by the Sun is four 
minutes longer than the day measured by the 
stars, and in a year the difference amounts to 
a whole day's time. Sidereal time would not do 
for the average unit of reckoning: "Sidereal 
noon," says one astronomer, "comes at all hours 
of the day and night during the progress of the 
year. Plainly, then, sidereal time is not a fit 
standard for regulating the affairs of ordinary 
life; for, while it would answer very well for 
a fortnight or so, the displacement of four 
minutes daily would in six months have all the 
world breakfasting after sunset, staying awake 
all through the night, and going to bed in the 
middle of the forenoon." Nor can the difficulty 
be altogether solved by taking any one solar 
day instead of the sidereal for measurement, for 
the Sun's apparent motion is beset with irregular- 
ities. Measured from meridian to meridian 
throughout the year, the solar days vary in 
lengths by many seconds. It is necessary, then, 
to find the average length of the total number of 
apparent solar days in the transit around the 
Sun, and this unit, called the mean solar day, is 



MOTHER EARTH 57 

the common measure of time, by which all the 
clocks and watches in common use are regulated. 
The rotation of the Earth, causing sunrise 
and sunset, also suggests a natural system of 
establishing directions. We have the cardinal 
points, east and west, north and south, and their 
divisions; we also have meridians and parallels, 
by which latitude and longitude are measured. 
Land surveys, by which boundary lines of real 
estate are marked, make constant reference to 
the cardinal points; boundary lines between 
states and nations are usually defined by mer- 
idians and parallels. Navigators have daily 
occasion to determine their position with respect 
to certain meridians and parallels to keep on 
in their desired route. In order that standard 
time may be kept throughout our country, the 
United States is divided into four time sections, 
each of which uses the mean solar time of its 
standard meridian. These meridians are exactly 
fifteen degrees, or one hour of time, apart. 
People traveling eastward across the United 
States advance their watches one hour on cross- 
ing each of these standard meridians; going 
westward the time must, of course, be turned 



58 MOTHER EARTH 

backward one hour at each meridian. These 
facts give rise to a number of interesting prob- 
lems, examples of which may be found in any 
text on arithmetic. Here is one selected at ran- 
dom: It is now 9 p. m. Tuesday, April 10, 
1876, at Ann Arbor, Michigan; over what part 
of the Earth is it Tuesday, and what day of the 
week is it over the remainder of the globe ? The 
answer is: It is Tuesday back to the east till 
we reach the point where it is midnight (i.e., as 
it is now 9 p. m., back 135° ) , and Tuesday west 
till we reach the 180th meridian. Between the 
180th meridian and longitude 51° 9' 12" east 
it is Wednesday. 

At midnight on Monday night at Greenwich, 
England, it is Monday all the way back to the 
east to the 180th meridian, and Tuesday all the 
way forward to the west to the same meridian. 
At the instant the midnight meridian coincides 
with the 180th, all the Earth has the same date 
day. In traveling eastward around the globe, we 
gain a whole day; and vice-versa, going west- 
ward, we lose a day. For convenience, there 
has been established in mid-ocean, closely follow- 
ing the 180th meridian from Greenwich, an 



MOTHER EARTH 59 

imaginary line, called the International Date 
Line. Thus, were you traveling from Califor- 
nia to China, and crossed the line on Monday, 
you . would see posted about the ship notices 
that having crossed the International Date Line, 
the date is changed from Monday to Tuesday. 
On the return journey, should you cross this 
line on Monday, you would see a notice advising 
the change of the date to Sunday. 

The chief effect of the Earth's revolution 
around the Sun, aided by the inclination of its 
axis, is the change of seasons, producing in turn 
spring, summer, autumn and winter, and the 
variations in the lengths of day and night. 
When the Earth is at A , March 21st, the spring 
or vernal equinox, it will be seen that the direct 
rays of the Sun fall upon the equator and that 
the great circle of illumination passes exactly 
through the poles. Day and night, therefore, 
are equal in all parts of the world. In the 
northern hemisphere are quickening Nature's 
coming signs of spring: "The melting of ice 
and snow, the gradual reviving of brown sods, 
the flowing of sap through branches apparently 
lifeless, the mist of foliage beginning to enshroud 



60 MOTHER EARTH 

every twig until the whole country is enveloped 
in a soft haze to palest green and red, gray 
and yellow." In the southern hemisphere au- 
tumn has come, and unmistakable signs show that 
winter is on the wing. Continuing on in its 
orbit the Earth arrives at B } the summer solstice, 
June 21. Now, it will be noted, the entire region 
within the Arctic Circle is in daylight, while 
the region at the opposite end of the Earth is 
in darkness. Now, too, as the great circle of 
illumination passes beyond the North Pole, the 
days in the northern hemisphere constantly in- 
crease in length, and on June 22 is registered 
the longest day and the shortest night of the 
year. On the other hand, the opposite condi- 
tions prevail in the southern hemisphere. As 
the Earth traverses from A to B the days grow 
constantly shorter and the nights longer. The 
increased length of day in the northern hemis- 
phere, of course, brings the conditions of sum- 
mer; while the shortening day in the southern 
hemisphere brings winter's ice and chill. When 
the Sun reaches C, at the autumnal equinox, 
September 22, the Sun's rays again fall directly 
upon the equator and the great circle of ilium- 



MOTHER EARTH 61 

ination passes through the poles; thus once 
more the days and nights are equal. Now, in 
the northern hemisphere the summer season 
passes into autumn, and in the southlands spring 
succeeds winter. At D, the South Pole now 
enjoys the Midnight Sun, while the North Pole 
is enshrouded in the gloom of the Polar Night. 
Likewise, too, the southern hemisphere is hav- 
ing summer; while our part of the hemisphere 
has arrived at the winter solstice, or December 
22, the date of the shortest day and the longest 
night. Now our part of the earth is tilted at its 
greatest angle away from the Sun. Now the 
trees stand dormant, their sap withdrawn far 
into their roots until the cold shall abate; the 
leaden skies swirl with snowflakes and all the 
Earth is hidden under a mantle of white. But 
now the world no longer trembles with fear 
lest these conditions prevail: we know that the 
Frost Giants can not long conquer, that 
presently the South Wind, "the summer-maker," 
will come, unlocking all fastnesses by his magic 
breath. 

It is a well-known fact that cold is apt to 
actually increase for a month after the Sun has 



62 MOTHER EARTH 

turned northward. Consider what it would 
mean if there were to be a permanent withdrawal 
of even a slight amount of the Sun's warmth: 
our Earth would freeze into perpetual winter. 
Again, a slight tilt of our axis might turn into 
Arctic regions those belts where the glory of sum- 
mer now reigns in its turn. But nothing is more 
stable than the laws of the Universe; all changes 
of movement and direction are slow and gradual, 
and we need not apprehend any change from 
the familiar variation of seasons, at least not for 
any period of time within the appreciable grasp 
of man. In late January, when the Sun 
has long been climbing steadily on his northern 
route, we begin to take note of the lengthening 
days, but the Earth has arrived back to the 
vernal equinox ere the astronomers whys and 
wherefores pale before that mysterious thrill 
when — 

"Every clod feels a stir of might, 
An instinct within it which reaches and towers, 
And groping blindly above it for light, 
Climbs to a soul in the grass and flowers." 

The Earth is made up of a vast number of 
elements, and its whole mass is estimated as. 



MOTHER EARTH 63 

six thousand millions of millions of millions of 
tons. This is an altogether incomprehensible 
term. Perhaps we shall convey a better idea 
if we state that the average weight of the earth 
is about 350 pounds per cubic foot. A cubic 
mile will, therefore, weigh in the neighborhood 
of 22,999,680,000 gross tons. The earth is not 
quite a perfect sphere, due no doubt to its 
centrifugal force when in a molten state. Its 
longest diameter is nearly 7,927 miles, and its 
shortest diameter nearly 7,900 miles; its average 
diameter then is 7,913 miles. Its average cir- 
cumference is calculated as 24,880 miles, and 
the area of its surface is 197,000,000 of square 
miles. It has a solid crust, but there has been 
much difference of opinion as to the composition 
of its center. All early astronomers considered 
this to be a molten mass; later a theory was 
put forward that the interior of the earth was 
in all probability a gaseous mass, the existence 
of volcanoes and hot springs being cited as proof 
of this supposition. 

One writer says: "In recent years the as- 
tronomer and physicist have collected evidence, 
which is as conclusive as such evidence can be, 



64 MOTHER EARTH 

that the Earth is solid from center to surface, 
and even more rigid than a similar mass of 
steel. Lord Kelvin shows that if the Earth 
were a fluid surrounded by a crust, the action 
of the Moon would not cause tides in the ocean, 
but would merely tend to stretch out the entire 
Earth in the direction of the Moon, leaving the 
relative positions of the crust and the water 
unchanged." 1 

Measurement of the temperatures in wells 
and deep mines shows that the average increase 
of temperature downwards is about one degree 
for every sixty feet. Down twenty-five or 
one-hundred miles we should naturally expect to 
find a very high temperature; indeed we know 
that this is true from the melted lava that rises 
and escapes from volcanoes. Newcomb, how- 
ever, says: "The matter of the interior of the 
Earth is kept solid by the enormous pressure. 
Thus, as we increase the temperature we have 
only to increase the pressure also to keep the 
material of the Earth solid. And thus it is, 
as we descend into the Earth, the increase of 
pressure more than keeps pace with the rise of 

i "Astronomy for Everybody," Newcomb. 



MOTHER EARTH 65 

temperature, and thus keeps the whole mass 
solid." This view is now generally accepted. 

Perhaps nothing about the Earth is more 
wonderful than its great transparent rim of 
atmosphere, reaching out into space to distances 
estimated as varying from forty-five to two- 
hundred miles. This atmosphere, or air, as we 
commonly term it, is composed of a mixture 
of gases, of which nitrogen and oxygen form the 
chief elements. Carbon-dioxide, which consti- 
tutes less than a thousandth part of the atmos- 
phere, is yet an element of untold importance, 
since it is necessary for the structural growth 
of plants. Winds — air in motion — supply the 
waves and currents of the ocean. Soil, which 
is formed largely from decaying rocks and vege- 
table matter, depends upon the action of moist 
air. Rainfall, too, comes from moisture sup- 
plied by evaporation in the form of clouds, which 
are carried about by air currents. Atmospheric 
pressure and the contraction and expansion of 
air solves the problems of weather. Fire and 
heat, so necessary in all operations of man- 
kind, could not exist without oxygen. All forms 
of life in the animal and vegetable world die 



66 MOTHER EARTH 

in a few hours, if oxygen is withheld. In short, 
without the atmosphere, the Earth would soon 
stand as dry and barren as the Moon, a dead 
and burned-out world, whirling aimlessly on in 
the ceaseless path from which it can never escape 
so long as the Sun holds sway over his realms. 



IV 

SOMETHING ABOUT THE OTHER PLANETS 

"If the comparison were not offensive to the 
Sun-god," says one of the well-versed astron- 
omers, "we might say that he is like a spider at 
the center of his web. In the net of his at- 
traction worlds are sustained. Relatively to his 
magnitude and might, the planets are but toys 
spinning round him." Yet we cannot realize 
the total extent of our solar system without 
a study of the marvelous array of planets and 
satellites, asteroids, comets, and meteors which 
revolve around our orb of day. 

The planets naturally divide into two well- 
defined groups of four bodies each: the inner 
and the outer planets, separated by the ring 
or circle of a third group called the asteroids or 
minor planets. In the first division, ranging 
from thirty-six to one-hundred-forty-one millions 
of miles from the Sun, are Mercury, Venus, the 



68 THE OTHER PLANETS 

Earth, and Mars. Next comes the 900 or 
more asteroids, the largest of which is not quite 
500 miles in diameter — less than the mean 
length of the state of Texas. In the outer group 
are the planets Jupiter, Saturn, Uranus, and 
Neptune, at a range varying from 482 to 2,789 
millions of miles. To remember the arrange- 
ment of the planets in relation to the Sun, here is 
a sentence, the first letters of each word of which 
furnish the key to the name of the planet : 

Men Very Early Made Jars Serve Useful Needs 

It means little to say that any one of the planets 
is a certain number of million miles from 
the Sun. We need a concrete example: Here 
is one, as set forth by Macpherson: "If we take 
a nine-foot globe to represent the Sun, we may 
represent Mercury by a large pea at a distance 
of 127 yards; Venus by a one-inch ball at 235 
yards; the Earth by a one-inch ball at 325 
yards; Mars by a half -inch marble at 495 
yards; the asteroids by 900 small seeds at dis- 
tances from 676 to 1,385 yards. Jupiter will be 
represented by an eleven-inch globe a mile away ; 
Saturn by a nine-inch globe one and three- 




BO VZ 

5 <» C c 

S? v. 

O t-i w 

o »c 

to Co 



00 JS^wT 

•* °° i-H 
00 . 

V F 3 3 

•r-l i-« C + J 



■s s ll 

O 1-1 <M 

c °° 

o 2 Mm 

a § c c 
SSSS 
S a §B 

b c f- 1 b 

0) a> rt ^ 



THE OTHER PLANETS 69 

fourth miles away; Uranus by a fourteen-inch 
globe five and one-half miles away. On this 
scale we can represent the Moon as a pea moving 
in a circle at a distance of thirty inches from the 
ball, one inch in diameter, which represents the 
Earth." 

Table Showing Actual Diameter of the Planets 

Inner planets: Mercury .... 3030 miles 

Venus .... 7799 

Earth .... 7913 " 

Mars ..... 4230 " 

The Asteroids, From 500 to 10 miles 

Outer planets: Jupiter 92,164 miles 

Saturn .... 74,000 " 
Uranus ..... 31,000 " 
Neptune 34,000 " 

From the above it will be noted that the 
inner planets are very much less in size than 
those in the outer circles, and that the asteroids 
are often "chips" of such small magnitude as to 
be scarcely worth counting. Indeed, the three 
groups are completely different not only in size 
and distance but in physical condition. More- 
over, certain of the planets are themselves the 
centers of particular little families of moons or 
satellites of their own. Mercury and Venus 



70 THE OTHER PLANETS 

have none. Indeed only two of the inner planets 
have satellites. We all know the Earth's sat- 
ellite, the Moon. Mars has two satellites, but 
both of these are smaller than our Moon. All 
the outer planets have an imposing circle of 
attendants. Jupiter has no less than nine 
moons, four large and five small. Saturn has 
ten attendants and a meteoric ring somewhat 
resembling small asteroids: Titan, the largest 
of these satellites, exceeds the planet Mercury 
in size, while the smallest are under thirty miles 
in diameter. Uranus has four satellites. Nep- 
tune, so far as we know, has but one. All of 
the paths or orbits of the planets lie in the same 
plane as the Sun, but all do not journey about 
him at the same rate of speed, as their velocity 
depends on their nearness to power of attrac- 
tion. 

Table Showing Velocities of the Planets 
Mercury 29 miles per second 2,505,000 miles per day 



Venus 


21 


Earth 


18 


Jupiter 


8 


Saturn 


6 


Uranus 


4 


Neptune 


3 



1,873,000 


>» 


» »j 


1,555,000 


»» 


>* * 


771,000 


»» 


»» M 


536,000 


>> 


** #1 


372,000 


» 


>i » 


268,000 


>• 


»» » 



THE OTHER PLANETS 71 

Neptune, our farthest known world, travels, 
it will be noted, the slowest of all, three miles per 
second, 268,000 miles per day, and yet we see that 
this pace must indeed be a terrible velocity. No 
other known agent goes with anything like this 
swiftness. How inconceivable, then, must be 
the speed of our own world, which seems to us 
so still and unmovable, but which really is carry- 
ing us onward through space at 1,555,000 miles 
per day; or, again, that of Mercury, which is 
rushing along 950,000 miles faster than we are! 
Flammarion gives this example: "A ball fired 
from a cannon leaves the mouth with a velocity 
of 1,312 feet per second, the terrestrial globe flies 
seventy-five times quicker, Mercury 117 times 
faster. This is a rapidity so stupendous that 
if two planets were to meet in their course the 
shock would be frightful ; not only would they be 
shattered in pieces, both reduced to powder, but 
further, their motion being transformed into 
heat they would be suddenly raised to such 
a degree of temperature that they would disap- 
pear in vapor — everything, earth, stones, water, 
plants, inhabitants — and they would form an 
immense nebula." (The nucleus for a new 



72 THE OTHER PLANETS 

world.) There is, however, absolutely no dan- 
ger of a collision. The planets are all going 
the same way, and are separated by enormous 
distances. Mars and the Earth, at their nearest 
approach, are 40,000,000 miles distant, while 
Venus our nearest "neighbor" is 25,000,000 
miles out in space. 

Of course, as the planets travel at different 
speed, and are placed at different distances, their 
path or orbit around the Sun is traversed in 
different time. Thus, Mercury, being the near- 
est of all to the Sun, has a much smaller ellipse 
to travel; it therefore goes much more swiftly 
around its orbit, accomplishing its journey in 
comparatively short order. 

Period of Planetary Revolution 

Mercury 88 days Jupiter nearly 12 years 

Venus 225 " 

Earth 365 " 

Mars 687 " 

It will be seen that our year of time as an 
element in the solar system is a very elastic 
quantity, depending entirely on the distance 
of a planet from the Sun. As one writer most 
cleverly points out: "A being who had lived 



Saturn 


30 


Uranus 


84 


Neptune " 


165 



THE OTHER PLANETS 73 

only twenty-four terrestrial years would be a 
centenarian on Mercury, while the man of 
eighty-four on our planet would be an infant 
of one year according to the length of years on 
the planet Uranus." 

Here is an experiment which will show the 
double motion of a planet revolving on its own 
axis and on its annual path around the sun. 
Take an ordinary dinner plate and half an egg 
shell. Moisten the rim of the plate and set the 
egg shell spinning on it. By tilting the plate 
a trifle, the egg shell will revolve in two direc- 
tions: first, on its own axis, and second, around 
the rim of the plate, which corresponds to the 
annual orbit of a planet on its course about the 
Sun. 

No less remarkable than our unit of time in 
various parts of the solar system is that of our 
measure of weight. On the Earth the weight 
of an article is the force with which the Earth's 
mass attracts that body. Therefore, as the 
masses of the planets vary, a body must have 
different weights in accordance with the planet 
on which it is weighed. For example, a man 
who weighs 165 pounds on the Earth would 



74 THE OTHER PLANETS 

weigh over two tons on the Sun. To express it 
differently, if you could take a one-pound weight 
and transfer it to the Sun, it would weigh twenty- 
seven pounds there. If you should try to raise 
your hat, you would find it weighed as much as a 
bucket of water on your head. In fact, you 
would hardly be able to lift your arms alone 
that far, as they would hang like lumps of lead 
against your body. And if you stooped to tie 
your shoe, you would be unable to lift your hun- 
dreds of pounds of weight again. 

Macpherson, further explaining this question 
of weight, says that a man weighing twelve 
stone 1 on our world "would weigh twenty-eight 
stone orf Jupiter, fourteen stone on Saturn, 
ten stone on Neptune, Uranus, and Venus. 
On Mars and Mercury the weight would be 
reduced to five stone, on the Moon to two, while 
on the asteroids it would come down to a few 
ounces. Let us suppose a man of twelve stone 
placed on the Moon. He would be amazed to 
find everything one-sixth as heavy as on the 
Earth. His own weight would be so diminished 
that he could jump over a house with as little 

i England's legal measure of weigjit, about fourteen lbs. 



THE OTHER PLANETS 75 

effort as he could on Earth leap across a way- 
side ditch. Pulling out his watch he would feel 
practically no weight at all. A horseman who 
on earth would consider a five-barred gate a 
good jump, would on the Moon leap over a 
hayrick with the same amount of exertion. Sup- 
pose a man were playing cricket on the Moon. 
On Earth 100 yards is a very good throw; on 
the Moon one of 600 yards would be accom- 
plished with the same amount of exertion. One 
able astronomer puts this lessened gravity very 
clearly : 'Football would show a striking devel- 
opment in lunar play; a good kick would not 
only send the ball over the cross-bar, but it 
would go soaring over the houses and perhaps 
drop in the next parish.' 

"Next let us suppose our man of twelve stone 
weight transferred to one of the outer asteroids. 
Here his weight would be only a few ounces. 
He would feel as light as a feather. When he 
jumped into the air, he could easily clear a house 
or a tree. Football would be an impossibility. 
A good-sized kick would send the ball up so high, 
it would leave the asteroid forever — and become 
a little asteroid on its own account." 



76 THE OTHER PLANETS 

One interesting writer speaks of the planets 
as "The Sun's Kiddies." Sir Robert Ball, in 
considering the planets as the Sun's family, says r 
"Venus and the Earth may be considered the 
pair of twins, alike in size and weight. Mercury 
and Mars are the babies of the system. The 
big brothers are Jupiter and Saturn." Accord- 
ing to one theory, the planets were originally 
parts of the Sun, and when they were thrown 
off by him, they continued to spin around on 
their own axis just as a ball continues its whirl- 
ing motion after it has left the pitcher's hand. 
Reason has already been given why the planets 
go on spinning and why they are held in their 
regular path or orbit around the Sun. Another 
theory, known as the Planetesimal Hypothesis, 
gives still a different origin of the planets, as we 
shall see later on when we come to study the nebu- 
lae, and it is no less interesting. 

Now let us find a way of telling the planets 
from the fixed stars. There are several ways 
of doing this : 

(1) Look for the planets along the same 
general direction or path in which the Moon 
seems to be traveling. 



THE OTHER PLANETS 77 

(2) If a planet is above the horizon, it is 
the first object to be seen in the sky in the 
gathering darkness just after sundown, being 
styled as an "Evening Star." (The calendar 
will tell you what planets are evening stars on 
any given date.) Following this same rule of 
brightness, the planets are the last to be seen 
in the sky just before sun-up. They are the 
"Morning Stars." Rising early one morning, 
the writer had a splendid view of Venus, Mars, 
Jupiter, and Saturn — almost the sole remaining 
bodies of an especially bright and interesting 
night-time sky. 

(3) None of the planets, except Mercury, 
twinkles, unless it happens to be near the horizon. 
They shine with a steady light, and their color 
names them: Mercury, pale ash; Venus, bril- 
liant straw ; Mars, reddish ochre ; Jupiter, bright 
silver; Saturn, dull yellow; Uranus and Nep- 
tune, pale green. Five of the planets shine at 
about the brightness of a first magnitude star. 
Venus and Jupiter* are a trifle the brightest; next 
Mars, Mercury, and Saturn in order. Uranus 
is about equal to a sixth magnitude star, and a 
few of the asteroids approach this. Neptune is 



78 THE OTHER PLANETS 

so far away that we glimpse him only as a star 
of the eighth magnitude, and then only through 
the telescope. 

(4) When you locate a "suspect" look at 
it several times in the course of a few hours. 
Compare its position with reference to some 
fixed stars or group, and see if you can determine 
whether it is in motion. If so, you may feel 
sure that you have found a planet. 

( 5 ) Astronomers find that the very best way 
to locate the planets is by photography. This 
is especially true if the work be among the 
asteroids. Frequently time exposures are made 
of certain fields of the heavens. These exposures 
may last an hour or more. If in the field of 
vision there are stars only, they will be photo- 
graphed as points of light. But if a small 
planet chances to be wandering along that way 
he will inevitably "make tracks" across the plate, 
and betray his presence by a continuous streak 
of light. 

(6) Few people, however, are in position to 
photograph the sky. The next surest and best 
way is to use an almanac or calendar which 
tells you which planets can be seen at certain 



THE OTHER PLANETS 79 

times of the year, and in what part of the sky 
they may be found. Then with a "sky map," 
or a good star atlas, one can first locate the 
planet on paper, then verify its position in the 
sky. 

MERCURY, THE SPARKLING ONE 

Mercury is the nearest known planet to the 
Sun. Indeed, so close does this "messenger of 
the gods" follow the Orb of Day that he is never 
to be seen above the horizon more than about 
two hours after sunset or the same time before 
sunrise, and during this period he always seems 
to twinkle violently because his rays must break 
through the thickest part of the atmospheric 
rim. He is as hard to follow in his course as it 
is to trace his nimble namesake in the metallic 
world. But though Mercury is an elusive 
planet, he has been known to mankind for so 
many centuries, that no one now knows who his 
discoverer was. The ancient Greeks knew him 
well, and always referred to him as "the spark- 
ling one." Three times during the year Mercury 
is morning star in the east, and three times he is 
evening star in the west. To determine the 



80 THE OTHER PLANETS 

proper periods of the year to look for him, you 
must refer to the almanac. 

Seldom can Mercury be found with the naked 
eye, nor does he yield any more readily to the 
telescope. He is usually so close to the Sun as 
to be overshadowed by the brilliance of that 
luminary. Like the other planets, Mercury is, 
of course, lighted by the Sun's rays, and he shows 
phases in the telescope just as the Moon does. 
One reason why Mercury is so hard to see is be- 
cause we never see him against a dark back- 
ground. When he does get on the opposite 
side of the heavens, the sun is between him and 
us. In other words, he is in opposition, as 
astronomers say when a planet lies in a straight 
line beyond the Sun. Now Mercury is the far- 
thest from the Earth, and were it not for the 
Sun shutting out our view, we should see the 
planet with a fully illuminated disc, or "full 
Mercury." Coming out from his sojourn in the 
solar glare, Mercury does duty as Evening Star; 
then, as it comes nearer and nearer the Earth it 
begins to show crescents, until presently we have 
"new Mercury," and like our satellite at new 
moon it becomes invisible. Now the Earth, 



THE OTHER PLANETS 81 

Mercury and the Sun are again in a straight 
line. But this time they are at conjunction, 
because the planet is in the same part of the 
zodiac with the Earth. Coming on its jour- 
ney Mercury soon appears as Morning Star; then 
again it shows crescents and finally disappears 
in the rays of the Sun to reappear again in its 
circuit as Evening Star. 

In our almanacs conjunction is shown by the 
sign <J ; opposition by 8. Suppose we turn to 
an almanac and note these signs 6 $ $ indicated 
on a certain date : Can you interpret the mean- 
ing? It is the astronomer's way of saying briefly 
that on this date a conjunction of Mercury and 
Mars will take place ; i. e. the two planets will be 
in a straight line and nearer to each other from 
our view than they will be again for a long time. 
Referring once more to the almanac we read 8 
B © : the interpretation is that on the date these 
signs are marked there will be an opposition be- 
tween Mercury and the Earth; i. e. Mercury will 
be beyond the Sun and therefore hidden from 
view. 

Mercury, you remember, is the swiftest of all 
the planets, rushing along at the stupendous 



82 THE OTHER PLANETS 

speed of twenty-nine miles per second, but it 
only makes one turn on its axis in its journey 
round the Sun. Thus it turns the same side 
always to the Sun just as our Moon does to the 
Earth. One side of Mercury is always flooded 
with perpetual sunshine, while the other is black 
as night. One side is baking hot, while the other 
is locked in icy throes. Small wonder that its 
surface seems cracked in all directions : "a geog- 
raphy in black and white." Owing to the ir- 
regular motion of the planet, and its slightly 
varying velocity, due to an erratic deviation in 
its orbit, there is a small zone on Mercury where 
the sun risers and sets. "In fact," says Mr. Gore, 
"an inhabitant living on the planet's equator 
would have forty-four days of sunshine and 
forty-four days of night and twilight. A little 
farther in on the dark side there would be perpet- 
ual twilight; and farther in still, eternal night 
would reign. Owing to the low altitude at- 
tained by the Sun near the bounding line, its 
intense heat and light would of course be much 
mitigated, so that probably this region of the 
planet's surface may be comparable with the 
temperate zones of the Earth." 



THE OTHER PLANETS 83 

It is the general opinion of astronomers, how- 
ever, that there are no dwellers on Mercury. 
At least, there can be no life there such as we 
know. Its surface is too rugged and mountain- 
ous, and it is extremely doubtful whether there 
is any atmospheric envelope. Of course there 
is no air, neither is there any water, but these 
points are debatable. "If there are inhab- 
itants of Mercury," says one writer, "they must 
from the dark side of their world, obtain mag- 
nificent views of the outer Universe. Venus and 
the Earth will shine with a glorious radiance, 
fully illuminated. The Earth and Moon seen 
from Mercury form a fine double star." 

Mercury is the smallest and lightest of the 
planets ; in fact, it would take twenty-five planets 
of his size to weigh as much as the Earth. Per- 
haps you wonder how we know this. An 
astronomer must be a wizard at calculation, and 
also what Edison terms a "good guesser." 
Ordinarily the easiest way of determining the 
size of a planet is by the attraction it has for 
its satellites : the problem is one of falling bodies, 
intricate enough, but also very exact, as proven 
by other rules. But Mercury has no satellite. 



84 THE OTHER PLANETS 

Other methods, then, had to be resorted to, 
and the result of one of these, as told by Sir 
Robert Ball, in one of the series of lectures 
which he gave in London more than thirty years 
ago, is wonderfully interesting and amusing : 

"There was once," said he, "and there is still, 
a little comet which flits about the sky; we 
call it after the name of its discoverer, Encke. 
There are sometimes splendid comets which 
everyone can see — we will talk about these after- 
wards — but Encke is not such a one. It is very 
faint and delicate, but astronomers are interested 
in it, and they always look out for it with their 
telescopes; indeed, they could not see the poor 
little thing without them. Encke goes for long 
journeys through space — so far that it becomes 
quite invisible, and remains out of sight for 
two or three years. All this time it is tearing 
along at a tremendous speed. If you were to 
take a ride on the comet, it would whirl you 
along far more swiftly than if you were sit- 
ting on a cannon-ball. When the comet has 
reached the end of its journey, then it turns 
round and returns by a different road, until at 
last it comes near enough to show itself* 



THE OTHER PLANETS 85 

Astronomers give it all the welcome they can, 
but it won't remain; sometimes it will hardly 
stay long enough for us to observe that it has 
come at all, and sometimes it is so thin and worn 
after all its wanderings that we are hardly able 
to see it. The comet never takes any rest; 
even during its brief visits to us it is scampering 
along all the time, and then again it darts off, 
gradually to sink into the depths of space, whither 
even our best telescope cannot follow it. No 
more is there to be seen of Encke for another 
three years, when again he will come back for 
a while. . . . And he is then so shy that usually 
very few catch a glimpse of him." 

Now it seems, to tell the story briefly, that 
an astronomer and a mathematician were great 
friends, and by giving heed to what the astrono- 
mer told him about Encke, the mathematician, 
who was what boys would term "a whirlwind 
at math," shortly figured out a route and a 
time-table for Encke. Moreover, it was abso- 
lutely correct, as subsequent visits of Encke 
proved. Thus, all went happily for some years, 
and then lo! Encke failed to appear according 
to schedule. 



86 THE OTHER PLANETS 

What was the reason? The two friends came 
well-nigh quarreling. But the mathematician 
was certain his figures were correct. Something 
had evidently happened to Encke. And shortly 
the truth of this was apparent. Encke turned 
up all right, but not exactly in the place he 
should have appeared; moreover there were 
several indications that he was considerably 
jarred and upset. Very plainly he had been 
mixed up in a tussle somewhere ! 

The mathematician looked over his figures 
and drawings. In one place along the route 
Encke came rather close to Mercury's orbit. 
"See what Mercury has been doing lately," 
shouted the mathematician, exultantly. 

The astronomer consulted his friends, and to 
his amazement found that erratic little Mercury 
had also been showing every indication of having 
been up to something, and the problem was 
solved. The mathematician, being also "a good 
guesser," had been able to lay his finger on the 
trouble. He knew that Encke had come near 
enough to Mercury to be drawn by his attraction. 
In short, the law of gravitation had very nearly 
worked chaos for Encke! The astronomer was 



THE OTHER PLANETS 87 

for dismissing the matter with perfect satis- 
faction, but not so the mathematician. 

"Wait a bit," he said. "It is the part of wis- 
dom to benefit by such mishaps. Let us see 
what actually happened to Encke. Let us meas- 
ure the distance between the place where Encke 
is, and the place where he ought to have been. ,, 

Subsequently the mathematician proved that 
Encke's delay was a measure of the mass of the 
planet, and triumphantly produced the figures 
which totaled the weight of Mercury's globe. 

VENUS, THE EVENING STAR 

Venus at her best is so much brighter than 
any of the stars or planets — twenty times 
brighter in fact — that one cannot help recogni- 
zing her on sight. But you must choose the 
right time to look for her: early in the morning 
in the east before the Sun is up, or in the west 
just after the Sun has gone down. Nor can Ve- 
nus be seen every day. You must consult the 
almanac for the time to look for her, as, like 
Mercury, she is invisible the greater part of the 
year. "When first seen as an evening star," 
says Ball, "Venus will often be like the Moon 



88 THE OTHER PLANETS 

at the quarter, and then it will pass to crescent 
shape. Then the crescent becomes gradually 
thinner, and next will follow a brief period of 
invisibility before the appearance of Venus as 
the morning star." 

Like Mercury, Venus makes but one rotation 
on her axis during the 225 days it takes her 
to go around the Sun, and she also keeps the 
same face toward the orb of day. Hence there 
are weeks at a time when she cannot be seen 
because of the Sun outshining her when she is 
between us and the Sun, or by being invisible 
because she is at the other side of the Sun. Both 
Mercury and Venus attain their greatest bril- 
liance when close to conjunction. For many 
days near this time Venus is visible in the clear 
blue even at mid-day, and she is often so daz- 
zling in the early evening as to give credence to 
marvelous tales. In 1887-88, so wondrous was 
her spectacle that she was hailed as the "Star of 
Bethlehem." In 1897, she shone forth with such 
splendor that a facetious newspaper reporter set 
adrift a tale citing her as an immense electric 
light, attached to a balloon, which had been 
sent up from the Edison laboratory to apprise 



THE OTHER PLANETS 89 

the world of the new light which had just been 
invented. 

Unlike Mercury, Venus runs nearly true on 
her orbit; hence one-half of her globe is always 
in the bright sunshine, while the other half is 
in darkness. Moreover, so dazzling is her light, 
which is, of course, simply reflected from the 
Sun's own gorgeousness, that we can not study 
her, even when she faces us plainly. Little, 
therefore, is known about the real surface of 
Venus. She seems to be rugged and mountain- 
ous, and in size very nearly approaches that of 
the Earth. More than one astronomer has fig- 
ured that Venus might be inhabited by mortals 
somewhat resembling ourselves. While she is 
nearer the Sun than we are, this does not neces- 
sarily mean a hotter climate. Other conditions 
of atmosphere might offset this. 

Something over a year ago, Marconi startled 
the world by the announcement that he had 
received wireless signals which led him to believe 
that we were being signaled by another planet. 
"They steal in at our stations at all seasons," 
said he. "We do not get the signals unless we 
establish a minimum of sixty-five mile wave 



90 THE OTHER PLANETS 

lengths. Sometimes we hear these planetary 
or interplanetary sounds twenty or thirty min- 
utes after sending out a long wave. They do not 
interrupt traffic, but when they occur they are 
very persistent. The most familiar signal re- 
ceived is curiously musical. It comes in the 
form of three short raps, which may be^inter- 
preted as the Morse letter 'S,' but there are 
other sounds which may stand for other letters." 

Australia immediately corroborated Marconi's 
statement. Highly skilled and experienced 
operators at Sidney reported frequent repeti- 
tions of two dashes, representing the letter M. 
They came in on wave lengths of 80,000 to 120,- 
000 meters. Such wave lengths are not in 
common use at any wireless station of the 
earth. 

Thomas A. Edison, commenting on the pos- 
sibility of such communications, said: "If we 
are to accept the theory of Mr. Marconi that 
these signals are being sent out by inhabitants 
of other planets, we must at once accept with 
it the theory of their advanced development. 
Either they are our intellectual equals or our 
superiors. It would be stupid for us to assume 



THE OTHER PLANETS 91 

that we have a corner on all the intelligence, 
in the Universe." 

If either Mercury or Venus at conjunction is 
near the node of the orbit, that is near one of 
the two points where the orbit intersects the 
ecliptic, or path of the Sun, the planet can be 
seen to pass across the Sun like a round black 
spot. This is called a transit. There are about 
thirteen transits of Mercury in a century, the 
shortest interval being three and one-half years, 
and the longest thirteen. As the Earth is near 
the nodes of Mercury's orbit in early May and 
again in November, it is in these months only that 
the transits can happen. Because Mercury's 
least distance from the Sun is at the November 
period, there are far more transits of Mercury 
in this month than in May. The Venus transits 
occur in pairs, eight years apart, during the 
months of June and December respectively, at 
intervals of 121J years and 105J years alter- 
nately, a June pair in one century being always 
followed by a December pair in the next. Both 
Mercury and Venus at transit are then nearest 
the earth, and their apparent motion is westerly 
or retrograde* (Tending backward.) For this 



92 THE OTHER PLANETS 

reason a transit always begins on the east side 
of the Sun. The last transit of Venus was in 
1882. Therefore no one of our readers will ever 
be able to see this wonderful phenomenon, which 
has always attracted the world of scientists, 
not so much for its beauty or its singularity, 
but because of the valuable information it af- 
fords. By taking certain measurements from 
both sides of the Earth of the displacement 
produced in the transit of Venus, mathemati- 
cians are able to calculate the distance of this 
planet, and knowing this they can also not only 
compute the distance of the Sun, but the distance 
and size of the other planets as well. This 
method of computing the Sun's distance is, how- 
ever, only of historical interest. Other and more 
accurate methods have displaced it. 

MARS, THE RED PLANET 

Mars has probably received more attention 
than all the other planets put together; because 
when it is nearest to us it turns its brightest 
side toward us, and at all times it is compara- 
tively free from heavy clouds, so that it may 
l?e readily observed. Mars ? too, may quite fre- 



THE OTHER PLANETS 93 

quently be seen with the naked eye. It comes 
into opposition with the Sun — that is, it rises 
in the east as the Sun sets in the west, and vice 
versa, showing its brightest and best at midnight, 
— about once in two years. When it is nearest 
the Sun — at perihelion, as astronomers say,' — 
it shines with a bright, steady, untwinkling red 
light. And from its color comes its name: red 
is the insignia of war, and Mars was the war god 
of the ancient Greeks. 

Mars is only a little over half as large as the 
earth ; its diameter is 4,230 miles ; its day is seven- 
teen minutes longer than our day, and its year 
is 687 of our days. If the Martian year were 
the same length as ours, Mars would come into 
opposition with the Earth at the same time every 
odd year. But the difference of forty-three 
days less than two of our years causes this op- 
position to vary about one month from one time 
to the next. By reference to a good almanac 
you will learn exactly in what month to expect 
Mars. Should the favored time be August or 
September then the planet will be at perihelion, 
and the sight will be very brilliant; but if the 
opposition is scheduled for February, the planet 



94 THE OTHER PLANETS 

will be at aphelion — the farthest from the Sun — 
and will shine with lessened brightness. 

Strangely enough, the red color which dis- 
tinguishes Mars is more noticeable when seen 
by the naked eye than when viewed through 
the telescope. The instrument shows the red of 
the planet splotched here and there with a dark 
greenish color. Astronomers think that the red- 
dish parts are continents, which are believed to 
be largely desert land, while the green parts 
betoken seas. If this be true, then Mars has 
vastly more land than water, — just the reverse 
of the conditions on the Earth. Another inter- 
esting feature is that the Martians, if there are 
any such people, can go from water to land 
without crossing wide oceans as we must do. 
The surface of Mars is relatively flat, and it is 
thought that for the most part the waters are 
not very deep. Extensive regions which show 
shades of orange and brown are thought to be 
marshes. Undoubtedly Mars is an older planet 
than the Earth, and astronomers agree that its 
areas of permanent water are gradually dimin- 
ishing. White spots at the polar ends of the 
planet are thought to be ice caps, because they 



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THE OTHER PLANETS 95 

always increase in size in the Martian winter, 
and fade when the Sun comes again, just as in 
our own polar circles. Indeed, Mars shows 
materially the same seasonal phases as the 
Earth. 

There has been endless speculation as to 
whether or not Mars is inhabited, and the 
majority of astronomers and scientists think that 
it is. But it is probable that the Martians are 
a people constituted differently from ourselves. 
Indeed, they needs must be; for the atmosphere 
of Mars is much thinner and rarer than our own ; 
besides, at sunset, the temperature falls alarm- 
ingly, reaching; at times 100 degrees below zero. 
Edmund Perrier, director of the museum of the 
Jardin* des Plantes, in Paris, gave to the world 
the first picture of the Martians, as he conceived 
them. "The men on Mars are tall because the 
force of gravity is slight," he said. "They are 
blond because the daylight is less intense. They 
have less powerful limbs. Their large blue eyes, 
their strong noses, their large ears, constitute 
a type of beauty which we doubtless would not 
appreciate except as suggesting superhuman 
intelligence." That the Martians, being an 



96 THE OTHER PLANETS 

older race, are beyond us in intellectuality may 
well be believed. 

Much excitement was aroused in the scientific 
world, in 1877, when Schiaparelli, the Italian 
astronomer, announced his wonderful discovery 
of streaks, or canals passing here and yonder 
on Mars. Many astronomers have since ver- 
ified the truth of this statement, among the 
most enthusiastic being the late Professor 
Lowell, director of the observatory at Flagstaff, 
Arizona, who looked upon the canals as direct 
evidence that Mars is inhabited by a people who 
thoroughly understood all the principles of 
intensive irrigation. To him it was plain that 
the temperate regions of Mars were an arid 
desert, and that to sustain their life the Martians 
had been compelled to intersect their country 
with a system of canals, and to bring water from 
the polar ice-caps. In 1914, the professor's 
belief was further strengthened by the discovery 
that two new canals had recently been built. 
"We have actually seen them formed under our 
eyes," he announced, "and the importance of it 
can hardly be overestimated. The phenomenon 
transcends any natural law, and is only explica- 



THE OTHER PLANETS 97 

ble so far as can be seen by the presence out 
yonder of animate will." 

All astronomers, however, do not agree to this 
interpretation of the black streaks which criss- 
cross the planet. Nor can their true explana- 
tion be verified until more powerful telescopes 
are made, or until that happy day when wireless 
is established with Mars. "To talk to Mars," 
says Nikola Tesla, "seems to me only a matter 
of electric power and perseverance." Professor 
Albert Einstein, whose relativity theories have 
lately made such a stir in scientific circles, 
thinks that the best medium for communication 
with the planets is the light ray. Photography, 
too, may develop further interesting features. 
Perchance some one of the boys or girls who 
read these lines may later solve this question of 
life in other worlds than ours. Meantime, even 
the best astronomers tell us that, after all, the 
merest amateur in astronomy really knows as 
much about it as they do, which is nothing at 
all. 

Early astronomers thought Mars an unat- 
tended body, like Mercury and Venus; but, in 
1877 , two satellites were discovered. These 



98 THE OTHER PLANETS 

moons of Mars are about seven miles in diam- 
eter. They are the smallest bodies known in 
the solar system, with the exception of the 
asteroid Eros. Professor Newcomb compares 
their size, as we see them, to a small apple viewed 
above Boston from a telescope in New York 
City. They can be seen only when the planet 
is near opposition, and then only through the 
large telescopes. Because of the brightness of 
the planet, we are told that the outer moon is 
easier to see than the inner one, although the 
latter is really the brighter of the two. Phobos 
and Deimos these two satellites are styled, in 
honor of the sons of the old war god. Phobos, 
the inner moon, is 4,000 miles from the planet, 
and goes around it in seven hours and thirty- 
nine minutes. Phobos, therefore, must seem to 
the Martians to rise in the west instead of in 
the east, as our Moon does. Furthermore it 
crosses the heavens three times in one day. It 
gallops across the sky, overtakes Deimos and 
eclipses him, we are told, and runs through 
all its phases in eleven hours. What a strange 
world where the moon could be seen early in the 
evening at the first quarter, and three hours 



THE OTHER PLANETS 99 

later at the full! Deimos takes a much more 
leisurely course than his brother; in fact he is 
about two and one-half days making his jour- 
ney. It would certainly be worth a journey to 
Mars just to see these wonderful moons! It is 
doubtful, however, if either of these orbs fur- 
nishes enough light to illuminate the evening 
skies. Perhaps we would do just as well to ob- 
serve them from here, apparently playing hide- 
and-seek with their planet, peeping out now on 
one side, now on the other. 

One astronomer, writing of the view of the 
Universe from the red planet, says: "Jupiter 
is magnificent from Mars; he appears to the 
Martians half as large again as he seems to us, 
and his satellites should be easily visible to the 
naked eye. Saturn is likewise very brilliant. 
Uranus is easily visible, and they might have 
discovered Neptune before we did. They must 
have distinguished with the naked eye a 
large number of the small planets which revolve 
between their orbit and that of Jupiter. 
Mercury, drawn closer to the Sun, and lost in 
his rays, is almost impossible to distinguish. 
Venus appears to them as Mercury does to us. 



100 THE OTHER PLANETS 

As for the Earth, how do we see it? . . . We 
are for that planet [Mars] a brilliant star 
presenting an aspect similar to that which Venus 
presents to us, preceding the dawn, and follow- 
ing the twilight ; in a word, we are to the inhab- 
itants of Mars the shepherd's star." * 

THE ASTEROIDS, OR MINOR PLANETS 

The asteroids, or planetoids, as they are some- 
times called, form the division between the inner 
and the outer planets, and the story of their 
discovery is another proof of the value of good 
guessing in the astronomical field. Such a vast 
space exists between Mars and Jupiter that it 
was early felt that a planet should be found 
revolving between the two. For more than 300 
years the search was carried on, and astronomers 
had about lost hope of finding the missing one, 
when Bode, a German astronomer, put fresh 
stimulus into the proceeding by a set of figures 
showing a curious relationship in planetary 
distances. By his rule — known as B ode's 
law — there was a missing link just where astron- 

i"The Romance of Astronomy," — Macpherson. 



THE OTHER PLANETS 101 

omers had long reasoned a planet should be found. 

Accordingly the Zodiacal region of the heav- 
ens, which is the path of the planets, was divided 
into convenient sections for observation, and the 
world of astronomers set themselves each to 
"policing" his own territory in the sky. But 
there were no results. What had become of the 
missing planet? 

Piazzi, the director of the observatory at 
Palermo, Sicily, found a hint of the solution, on 
the first night of the nineteenth century. While 
making observations for the purpose of putting 
out a star catalogue, he noted an eighth mag- 
nitude star which was new to him. Observing 
this star a second night, how was he surprised 
tq note that it was in motion! It was, then, 
not a star; no doubt it was a comet. But it was 
tailless, and it had none of the comet's eccen- 
tricities. Could it possibly be the missing 
planet? Piazzi made a chart as best he could, 
and sent his information to Bode. On account 
of illness, the director was then forced to leave 
his post for six weeks, and ere his return the 
planet had disappeared. All feared that it had 



102 THE OTHER PLANETS 

gone beyond recall, but happily mathematicians 
managed to calculate an orbit from Piazzi's 
notes, and on the last day of the century the 
planet hove into sight again, just as the math- 
ematicians had figured that it would do ! Ceres, 
it was called, in honor of the guardian goddess 
of Sicily. 

To be sure, Ceres was only a small planet — 
480 miles in diameter; nothing at all like what 
they had expected to find. But she filled the 
gap, and astronomers felt that they must be 
satisfied. Imagine, then, their surprise, as the 
most of them went about other business, when 
three months later, Olbers, a German astron- 
omer, discovered another planet not far from 
Ceres. Pallas, they called it, and it was soon 
seen that both of the new planets revolved about 
the sun at nearly the same distance. 

What did this mean? For now the sym- 
metry of the solar plan was broken. Undoubt- 
edly the two bodies were related, and presently 
it was decided that at some period a planet, 
similar perhaps to Mercury, had existed between 
Mars and Jupiter. Age, or some catastrophe, 
had dissolved it, and the two small planets were 



THE OTHER PLANETS 103 

the "remnants." This opinion was further 
strengthened by the discovery of Juno, in 1804, 
and Vesta, in 1807. No further planets having 
been discovered after a period of careful search, 
the theory was regarded as fully established, and 
for forty years no one thought of questioning it. 
Then, rapidly one after another, due no doubt 
to the increased power of the telescope, astron- 
omers here and there began to discern other 
small planets, and again the search for planetoids 
was begun with feverish eagerness. Presently 
so many had been definitely located as to make 
the effort of naming them absurd. It was sug- 
gested that the letters of the alphabet be ap- 
plied, but these soon proved altogether inade- 
quate, and the process was begun over, designat- 
ing the additions AA, BB, etc. This, of course, 
was confusing, and not sufficient either, and, 
after a time, the sensible plan of numbering the 
planets was adopted. To-day the latest addi- 
tions are catalogued up in the nine hundreds, 
and astronomers are no longer specially inter- 
ested in the planetoids. Of them all, a little 
asteroid, called Eros, which was discovered in 
1898, is the only one that has served any partic- 



104 THE OTHER PLANETS 

ular purpose. Unlike its kindred, Eros does 
not travel in the field between Mars and Jupiter ; 
its orbit is so elliptical that once in thirty years 
it comes within the orbit of Mars, and is then 
our nearest planet neighbor, only 13,500,000 
miles away. At this distance, it has been photo- 
graphed many times, and by measurements thus 
secured, astronomers, who never like to rely on 
any one method, have been furnished with an- 
other means of calculating the solar dimensions. 

It is hardly probable that any living beings 
are to be found on the asteroids. Certainly they 
would have to be of a totally different nature 
from any creatures known on our Earth. 
Suppose the planets to be of the same density 
as our sphere, on a planet one hundred miles 
wide, — one-eightieth of the diameter of the 
Earth — every weight would be reduced to an 
eightieth part of what it is here. The average 
man, then, would only weigh about a couple of 
pounds, and as Professor Ball points out, such 
a creature might easily possess a pair of wings 
and be able to fly, provided the atmosphere were 
conditioned like our own. 

This writer gives an entertaining picture of a 



THE OTHER PLANETS 105 

game of lawn* tennis under such conditions — 
which at best would be a difficult pastime. 

"The very slightest blow of the racket would 
drive a ball a prodigious distance before it 
could touch the ground ; indeed, unless the courts 
were about half a mile long, it would be impos- 
sible to serve any ball that was not a fault. 
Nor is there any great exertion necessary for 
playing lawn tennis on Flora, even though the 
courts are several hundred acres in extent. As 
a young lady ran to met the ball and return it, 
each of her steps might cover a hundred yards 
or so without extra effort; and should she have 
the misfortune to get a fall, her descent to the 
ground would be as gentle as if she was seeking 
repose on a bed of the softest swan's -down.' ' 

We know practically nothing of the real 
condition of the asteroids. The majority of 
them can be seen only through the most powerful 
telescopes. No traces of atmosphere round 
them has been found. Nor has it been possible 
to determine their rotation or surface conditions. 
Some show such variations of light that it is 
probable they have rugged outlines on which the 
light reflected from the Sun varies according to 



106 THE OTHER PLANETS 

their position. We do know, however, that 
the old theory of their origin from a wrecked 
planet is without foundation. Astronomers are 
now satisfied that rings were thrown off from the 
nebula in space, and that these should have united 
to form a large planet. But owing to the im- 
mense attraction of Jupiter such a condensation 
of rings was impossible. Thus these innumer- 
able bodies, each pursuing its own appointed 
path around the Sun, serve as one of the wonder- 
ful niceties of the harmony and balance existing 
in our Universe. 

JUPITER, THE GIANT PLANET 

Jupiter is the mightiest of the planets, so 
great indeed that all the other planets and their 
satellites rolled into one could not fill the space 
he occupies. Beside him, our Earth seems 
insignificant; 1,200 globes of our sphere's size 
would not quite cover this immense planet. 
Jupiter is 483,000,000 miles from the Sun. His 
diameter is 87,000 miles. His year is almost 
twelve of our years long. But his day is only 
ten hours in length, which means that Jupiter 
in spite of his immensity, is rotating on his axis 



THE OTHER PLANETS 107 

so quickly that eveiy five hours the side of the 
planet which is toward us presents an altogether 
new view. 

When Jupiter is in opposition to us he pre- 
sents a sublime spectacle. This occurs about 
once in every thirteen months, and he reaches the 
meridian at midnight. Just as the Sun is sink- 
ing, this big bright star rises in the opposite 
horizon, showing clearly at twilight and growing 
more brilliant as the night advances and he as- 
cends the sky. It is impossible to mistake him. 
He shines supreme — a bright, particular king. 

Since Galileo, in 1610, pointed his newly 
invented telescope — the first instrument of the 
kind the world had known — at Jupiter, this 
silvery body has been the delight of astronomers, 
from the merest amateur to the most expert. 
Even the smallest instrument will show that the 
wonderful radiance comes from a round disc- 
like body, which is obviously a planet, and will 
give a glimpse of the four largest satellites — 
moons which run through all sorts of brisk and 
lively changes and eclipses, and which it is 
thought, may possibly be inhabited, the larger 
exceeding the size of the planet Mercury. These 



108 THE OTHER PLANETS 

moons of Jupiter, too, are interesting from an- 
other point: it was their eclipses which first 
suggested to astronomers and mathematicians 
that light had a measureable speed. To-day we 
know that light rushes along so swiftly that it 
could go more than seven times around the earth 
in a single second, its velocity being, in truth, 
186,300 miles per second. Altogether Jupiter 
has nine moons. The innermost one flies around 
him in about eighteen hours ; but the outside one 
takes nearly seventy days to perform the revolu- 
tion. 

Jupiter is of vast interest because it is evi- 
dently a world in the making. Great clouds rise 
from it in immense volume, showing that it is 
still terrifically hot, no doubt yet in a semi- 
liquid and gaseous condition. It is thought, 
however, that the light which it casts is not from 
its own heat. It has cooled sufficiently to reflect 
the Sun's rays, but not enough to maintain water 
on its surface. Doubtless a great part of 
Jupiter's size is due to its inflated, gaseous con- 
dition; for by means of its moons, incredible as 
it may seem to us, mathematicians have suc- 
ceeded in weighing the great planet's mass. 



THE OTHER PLANETS 109 

They tell us that it weighs only 300 times as 
much as the earth. 

When viewed through the telescope the vast- 
ness and diversity of Jupiter's landscape become 
more apparent. The equator is partly hidden 
by huge belts of reddish clouds some of them as 
big as our whole Earth. The equatorial belt is 
yellowish or tan color where visible, but constant 
cloud masses break it up. Toward the temper- 
ate and frigid zones these clouds become steel- 
blue and gray, showing that the Sun exercises 
less and less effect toward the poles. 

As for Jupiter's position in reference to our 
universe, we are told that if it were possible for 
us to be transferred to the great planet, and 
if we could see through the cloud belts, the 
Earth would be scarcely visible, being only seen 
with difficulty in the vicinity of the Sun. The 
constellations in the heavens, however, would be 
those with which we have long been familiar; 
for the 390,000,000 miles which separate us from 
Jupiter is a mere nothing in the celestial per- 
spective. Unquestionably the most curious spec- 
tacle from the Jovean realm would be its own 
marvelous moons. To these Jupiter is himself a 



110 THE OTHER PLANETS 

miniature sun, giving out a certain amount of 
heat as well as reflected light. 

Galileo's discovery of the four large moons of 
Jupiter was the best possible proof of the 
Copernican theory. Here on a plane easily 
discernible was a reproduction of the solar sys- 
tem which should convince the most skeptical. 
But certain prejudiced opponents of the system, 
it is said, refused to look through the telescope; 
others, and perhaps the most stiff-necked, looked 
and refused to credit the spectacle, saying that 
the satellites were in the telescope, not in the 
sky! The four moons, named in order of size, 
are Ganymede (III); Callisto (IV), Io (I), 
and Europa (II) ; but they are most commonly 
known by their numerals, which indicate their 
nearness to Jupiter. 

SATURN, URANUS AND NEPTUNE 

Saturn is the farthest planet that can be 
easily observed with the naked eye, and then he 
appears only as a star of the first magnitude, 
about the brightness of Capella in the constella- 
tion of Auriga. There is one advantage, how- 
ever, when he rises at sunset he can be seen dur- 



THE OTHER PLANETS 111 

ing the whole night, so that one has not only 
plenty of time to find him but to observe him 
as well. Moreover, he recurs night after night 
for several months. The ancients thought little 
of him; indeed they considered him an unlucky 
planet, slow of motion, dull of light, and alto- 
gether a symbol of gravity and gloom. Persons 
so unfortunate as to be born under his sign were 
sure to be dull and morose in nature, "saturnine." 
Under the powerful telescopes of to-day, how- 
ever, Saturn takes on an altogether different 
hue. So far from being the least interesting 
of the planets, he is indeed altogether the most 
fascinating and unique. To the best of man's 
knowledge there is none other like him in our 
universe. 

What we see through the powerful lenses is 
a glorious dull yellow orb, striped with belts 
similar to those of Jupiter, but fainter owing 
to its great distance. (Saturn is sometimes 
nearly a thousand million miles from us.) 
Around the planet is a wonderful system of 
three rings — two bright, and one of semi-trans- 
parency, called the crepe ring. The rings, it has 
been found, are made up of millions of little 



112 THE OTHER PLANETS 

pieces, tiny moons or satellites in themselves. 
The moons may be separated from one another 
thousands of miles, but at this distance they 
show as a complete circle or ring. Moreover 
these magnificent rings, taken together as a plate 
or rim, are not less than 176,000 miles in diam- 
eter, 30,000 miles in width, and from fifty to 
one hundred miles thick. Our Earth could 
revolve on this "celestial deck," as Flammarion 
puts it, "like a ball rolling along a road." More- 
over, the planet in the center is more than 900 
times the size of our sphere. The ring system 
however, may be a transient feature, another 
satellite in process of formation. 

Saturn has ten known moons, each revolving 
in its well-appointed orbit, and depending on 
him not only for heat but as the giver of light. 
Should any of these satellites have inhabitants, 
they probably regard their planet much as we do 
our Sun. Titan, the largest of these worlds, 
equals the planet Mercury in size. Themis, the 
smallest yet known, is discernible only by pho- 
tography. Phoebe, the. most distant of Saturn's 
satellites, is the most remarkable little moon in 
existence, possessing an independent spirit that 



THE OTHER PLANETS 113 

is both staunch and unique. Usually members 
of the solar system travel eastward, or from the 
west to the east; but not so Phoebe. For some 
reason unknown she pursues a contrary course, 
going westward, or from east to west. One may 
imagine the confusion of Saturn's evening skies, 
with nine moons flying along, one after another, 
each one taking its own time to complete the 
revolution — the nearest, little Mimas, being over 
two days on the job, for Saturn's day, you 
remember, is only ten hours long — then contrary 
little Phoebe sailing along majestically in the 
opposite direction and openly voicing her de- 
fiance to regulation by leisurely taking sixteen 
months to perform her voyage ! 

Not only is Saturn remarkable for the strik- 
ing spectacle of his rings and moons, but he is 
the lightest of the large planets, being only 
ninety times heavier than the earth, notwith- 
standing the fact that he is over 700 times larger. 
Indeed, says one authority, "Saturn is only equal 
in weight to a globe of walnut wood of the same 
size. In fact, if we could imagine a great ocean 
large enough to hold the various planets, and if 
we could imagine the planets thrown one by 



114 THE OTHER PLANETS 

one into that ocean, Saturn would actually float 
while all the others would sink." Of course 
this extraordinary lightness of the planet can be 
explained in only one way; Saturn, like Jupiter, 
is in an early stage of development. The vast 
clouds which rise from its surface betoken a 
state of chaotic existence — violent eruptions, 
seething boiling masses of inflammable elements, 
clouds of gas*, and a sweltering heat. 

The planet Uranus can sometimes be seen in 
the spring and summer months, shining with a 
pale green light, if you have a good eye and know 
just where to look for him. It is probable that 
the world marked him as a star for centuries. 
Any real knowledge that has been had of him 
has, of course, come through the most powerful 
telescopes; though Herschel, the German 
astronomer who first sighted the planet, was a 
mere amateur, a musician by trade, who worked 
with a home-made telescope. Uranus is 1,780 
millions of miles from the Sun, and has a diame- 
ter of 32,000 miles. His day is thought to be 
about eleven hours long, and his year is eighty- 
four of our years long. By the aid of his four 



THE OTHER PLANETS 115 

satellites, Uranus, though such a vast distance 
from the Earth, has been weighed in the mathe- 
matical scales and found to be about fifteen times 
heavier than the earth. The spectroscope has 
proven that the planet has an extremely dense at- 
mosphere. The two inner satellites of Uranus 
are about 500 miles in diameter; the outer ones 
are nearly twice as large. Like Phoebe, they 
choose to travel in contrary motion, that is from 
east to west, or as astronomers say their motion 
is retrograde. 

While astronomers were busy studying Ura- 
nus, in order to discover as much about its con- 
dition as possible, careful observers soon took 
note of its eccentricity. It did not follow the 
exact path which, the mathematicians figured 
that it should. Evidently something was inter- 
fering with its motion. What could it be? 
Was there yet another planet beyond this one? 
Two young students, one at Cambridge, Eng- 
land, named Adams, and the other Le Verrier, 
a Frenchman, set out to figure an orbit such 
as it was probable the unknown planet, if there 
were one, was traveling. Neither knew of the 
other's plans, and it chanced that Adams finished 



116 THE OTHER PLANETS 

his calculations first and sent them in to the 
Royal Astronomer, Airy, a former professor 
of Cambridge. It happened that the great man 
was extra busy, and he put the memoranda in 
a pigeon-hole and forgot all about them. When 
Le Verrier finished his drawings and conclu- 
sions, they chanced to meet Airy's eye. Happily 
the professor now remembered young Adams' 
offering, and on bringing it to light, found that 
the two young men had arrived at the same con- 
clusion. This was a marvelous coincidence; 
probably nothing more. But the professor made 
haste to have their suggestion tested, and there 
indeed was the disturber of Uranus, a planet 
showing a greenish disk of light. About the 
same time, a like test was made at the Berlin 
observatory, by Dr. Galle, at Le Verrier's request 
with the same results. There could be no doubt, 
then, that a new addition had been made to the 
solar system, and the new wanderer was shortly 
christened Neptune. 

The planet is altogether invisible to the naked 
eye, but it is sufficiently bright to have been oc- 
casionally recorded in old star maps as a star. 
Indeed, some fifty years before it was named a 



THE OTHER PLANETS 117 

planet, the astronomer Lelande included it in a 
list of stars he was making, setting down in his 
diary some observations which later marked him 
as a sorry blunderer. It seems that he had ob- 
served the star and noted its position on May 
8, 1785. Two days later he noted that the star 
was not in the position he had indicated. He, 
therefore, concluded he had made a mistake the 
first time, and accordingly moved the star on his 
plot. But the point of light was not a star; it 
was a planet. Its movement should have re- 
vealed the fact to Lelande, but he unwittingly 
let this proof slip by, and thereby catalogued 
himself in the world's records as a heedless as- 
tronomer, instead of a man of renown. Seldom 
has anyone more narrowly escaped fame! 

Neptune is at such a remote distance, — half 
as far again from the Earth as Uranus — that we 
can scarcely hope ever to know very much about 
him. His diameter is 36,000 miles; he is, there- 
fore, a little over four times the width of the 
Earth, thus holding the same proportion to our 
sphere as the Earth does to the Moon. Like his 
great kindred, Neptune is hidden in dense clouds, 
and it has been determined that his weight is only 



118 THE OTHER PLANETS 

one-fifth of what it would be if he were made of 
earthly elements. He is, in all probability, com- 
paratively in his infancy. His year is known to 
be 165 of our years long, but the length of his 
day has not been determined. 

Are there other planets outside of Neptune? 
Can we consider it, as Macpherson queries, "the 
frontier of the Sun's domain"? Astronomers 
are not yet ready to answer this question. Be- 
cause of unexplained influences affecting certain 
comets, many believe that there is still another 
planet in the Sun's family. We have only 
known of the existence of Neptune for about 
seventy years. Perchance ere the century ends 
some one may be ready with a solution of the 
query. 



THE MOON, A D'AUGHTER OF THE EARTH 

The ancients named the first day of the week 
Sun-day, in honor of the sun-god. Likewise, 
the second day was named after the next most 
important celestial body — the moon — Moon-day, 
which common usage has shortened to Monday. 
Though the Moon is our nearest neighbor in 
space, so near that its distance may be counted 
in thousands of miles, it is yet a long way off — 
about 240,000 miles. "If you were to wrap a 
thread ten times round the equator of the Earth," 
says Professor Ball, "It would be long enough 
to stretch from the Earth to the Moon. Or 
suppose a cannon could be made sufficiently 
strong to be fired with a report loud enough 
to be audible 240,000 miles away. The sound 
would only be heard at that distance a fortnight 
after the discharge had taken place." An ex- 
press train, traveling at the rate of sixty miles 
an hour, and stopping neither night nor day, 

119 



120 MOON, DAUGHTER OF EARTH 

would reach the Moon in about five and one- 
half months. 

No explorer has ever visited our satellite, and 
it is not probable that one ever will; yet we really 
know more about the geography of the Moon 
than we do of some parts of the Earth. Take 
the dark continent of Africa. Here are wide 
tracts of forests, great lakes, and lofty moun- 
tains of which little is known. While, on the 
side of the Moon nearest us, there is scarcely a 
spot as large as the average county which has 
not been mapped and photographed many times. 
Astronomers have painstakingly built up great 
charts of the Moon, as large as good-sized 
garden plots. One of the most notable of these, 
the work of Johann Schmidt, was begun when 
the great German astronomer was only a lad 
of fourteen, and was completed shortly before 
his death, forty years later. All points of lunar 
interest are, of course, carefully named on the 
various maps and charts, and astronomers 
are probably more familiar with the terms 
Eratosthenes and Tycho than you are with 
Vesuvius and Kilauea. 

A favorite theory is that the Moon was once 



MOON, DAUGHTER OF EARTH 121 

a part of the Earth. To throw off such a 
mighty part of its bulk — one-fourth of its size, 
to be exact — the Earth must have been whirling 
on its axis at a terrific rate; making a complete 
revolution about once in two hours, it is figured, 
instead of once in twenty-four hours, as it now 
does. Thus the centrifugal force was enough 
to overcome the force of gravitation, and the 
Moon was torn out from the Earth's side and 
thrown into an orbit of its own. Certain astron- 
omers believe that the "hole" thus left in the 
Earth is now filled by the waters of the Pacific 
Ocean, and there are some very likely proofs: 
(1) If the waters of the Pacific could 
be rolled into a ball, their bulk would be just 
about the size of the Moon. (2) The coasts 
which surround this ocean are roughly circular 
in form. (3) There is a great similarity be- 
tween the volcanoes of the moon, and those of 
California, the Hawaiian Islands, and Japan; 
but what caused these volcanoes can only be 
guessed at. One theory is, that when the separa- 
tion took place, great showers of melted lava 
were thrown out and fell, settling in gigantic 
masses both on the Moon and on the Earth in 



122 MOON, DAUGHTER OF EARTH 

the vicinity where the pent-up gases issued. 
Many of the volcanoes so established are still 
active on the Earth, but those of the Moon are 
dead, because the Moon being so much smaller 
than the Earth cooled more rapidly, and thus 
the internal fires necessary for volcanic out- 
breaks were soon quenched. 

Though the Moon is the Earth's daughter, she 
is not a world like ours is to-day. She is a type 
of what the Earth may be ages hence. For the 
Moon is cold and dead; her life fires have long 
since burned out. She is a "closed chapter in 
the book of time." As Flammarion points out : 
"In space there are both cradles and tombs." 
Jupiter, Uranus, and Neptune, as we have seen, 
are in the cradle stage. The Moon is one of the 
tombs of the Universe. Bleak and bare and 
still she is; without air, or water, or life of any 
form. Besides her mountains and craters and 
consequent valleys, the Moon has great gray 
stretches, which the early astronomers thought 
to be seas and named them accordingly, the 
"Sea of Serenity," "Sea of Tranquillity," etc. 
It is now known that there are no seas on 
the Moon, The gray stretches are simply vast 



MOON, DAUGHTER OF EARTH 123 

dead planes; perchance ocean beds from which 
the water has long since disappeared. But the 
names have been retained as a matter of con- 
venience. The mountains of the Moon have 
been called after those of the Old World. 
There are the Alps, the Apennines, and the 
Carpathians. The two highest ranges, Doerfel 
and Leibnitz, are from 30,000 to 36,000 feet, 
much exceeding the highest mountains on the 
Earth. More than forty lunar peaks have been 
noted which exceed Mont Blanc. Todd ex- 
plains the greater height of the mountains on 
the moon as due to the lesser surface gravity of 
our satellite. Perhaps the reader may wonder 
how the height of mountains on the moon can be 
determined? The answer is by measuring the 
shadows which they cast. 

The craters on the Moon get their names from 
ancient scientists: Tycho, Ptolemy, Coper- 
nicus, Plato, Archimedes, etc. Some of these 
craters are enormous. The walls of Copernicus, 
for example, are about fifty miles thick, and 
over two miles high. All about this great disc 
the surface is rugged in the extreme, and from 
its center rises a cluster of conical mountains. 



124 MOON, DAUGHTER OF EARTH 

Triesnecker, another remarkable crater, has a 
mysterious system of cliffs or chasms, a mile 
across at their widest point, and some 300 miles 
in breadth. Some astronomers credit this won- 
drous spectacle as the path of an ancient river 
bed. Similar to the craters in formation are the 
great walled plains, often 150 miles across, sur- 
rounded by mountainous ramparts, rising often 
12,000 feet above the enclosed plain. Rills is 
the name given to a series of great yawning 
chasms, which run for miles, in fairly straight 
lines, over craters, mountains and plains, across 
portions of the surface of the Moon. Some 
astronomers regard the marvelous array of ir- 
regularities on the Moon's surface as proof that 
neither water nor atmosphere has ever been 
present on our satellite. 

The Moon takes as much time to turn on its 
own axis as it does to go around its orbit — about 
twenty-eight days. So that, like Mercury and 
Venus, the Moon's day and year are of the same 
length. For this reason, too, the same side of 
the Moon is always turned toward the Earth; 
and thus it follows that the lunar days and 
nights are about as long as fourteen of our days. 



MOON, DAUGHTER OF EARTH 125 

The Moon's actual distance around the Earth 
is a little longer than its distance around its 
orbit from a certain fixed star back to the same 
star again; thus the Moon, like the Earth, has 
two days, or rather periods, as the astronomers 
term them: the synodic period and the sidereal 
period. The synodic period is equal to about 
twenty-nine and one-half of our days, and from 
this division of time the ancients got the idea 
for the month. 

Since the same side of the Earth is always 
turned towards the Moon, of course it follows 
that we really know only one-half of the Moon. 
But as she sways slightly in her orbit, astrono- 
mers occasionally catch glimpses of the other 
side, and in this manner it is judged that the un- 
seen part is in keeping with the side which is in 
full view. The Moon is not always the same 
shape, nor does it always appear at the same spot 
in the sky. The "Inconstant Moon" Shake- 
speare terms her. The changes in the Moon's 
shape are called its phases, and these phases are 
governed by the Moon's position with regard to 
the Sun. For the Moon is herself a dark body, 
and the light she shows is all reflected from the 
Sun. 



126 MOON, DAUGHTER OF EARTH 

A simple little experiment will show you how 
it is that the Moon shows phases, for of course 
she does not change her shape; the whole round 
Moon is always there, only part of it is in the 
shadow. Hang a rubber ball from the ceiling 
in the center of a dark room. Then set a lamp 
to represent the Sun in such a manner that its 
beams fall squarely on the side of the ball, which 
you are to fancy as "the Moon." Now, as you 
look at the Moon from squarely in front of it, you 
see the whole bright side. It is full moon. 
Moving a little farther to one side, either way, 
the Moon looks nearly full — foot-ball shape, in 
fact. This is the gibbons moon. Going a little 
farther, we see only a quarter of the ball. This 
is the half moon, or as it is more commonly 
called the first or last quarter, depending on 
whether it is west or east of the Sun. A little 
farther and only a slim crescent is seen. This 
is the new crescent, or the old crescent Moon, 
depending on direction as above. Going on 
still farther you find the Moon between you and 
the Sun. Its dark side is toward you, and it is 
therefore invisible. This is the new moon. 

You will find it most interesting to follow a 



MOON, DAUGHTER OF EARTH 127 

course of the Moon's phases. Watch your 
calendar for the date when the new moon is due. 
You won't be able to see it, of course, but two 
or three days later you may expect the new 
crescent low in the western sky, with her horns, 
or cusps, turned toward the east. Now, too, 
you may perhaps catch a glimpse of the "old 
Moon in the new Moon's arms." This is an 
interesting phenomenon. What we see is the 
dark globe of the Moon apparently filling the 
slender {silvery crescent-like arms of the new 
Moon. But probably you would never guess 
why this is to be seen. It is earth-shine. The 
Suns' rays are reflected from the Earth to the 
Moon, so that the Moon is lighted with earth- 
shine just as the Earth is lighted with moon- 
shine, and it is these reflected rays that light up 
the dark part of the Moon, causing it to ap- 
pear embraced by the crescent made by the Sun. 
Think what a marvelous journey these light rays 
have had! From the Sun to the Earth, then 
back to the Moon, and down to the Earth again! 
The Moon moves eastward among the stars 
of the zodiac at the rate of about thirteen degrees 
each day; hence she appears to us about fifty- 



128 MOON, DAUGHTER OF EARTH 

five minutes later each night. When the Moon 
is near the quarter phase, her shape is a good 
guide to mark out the path of the ecliptic. Join 
her horns by an imaginary line; then a line 
standing perpendicular to this line, extended 
both ways, will very nearly point the path fol- 
lowed by the Sun. The small crescent Moon 
shines through only a small part of the night, 
the half Moon gives its light for half of the night, 
and the full Moon, although it rises a little later 
each night, shines all night long. About the 
time of the autumnal equinox, September 21, 
when the days and nights are equal, the full 
Moon rises at nearly the same hour for several 
nights in succession. This is called the Harvest 
Moon. The October full Moon is the Hunter's 
Moon. 

All of you have seen "the Man in the Moon," 
and doubtless you know, too, that the markings 
which seem to portray the human face are, in 
truth, actual configurations of the Moon's sur- 
face. The ancients were much exercised 
about these dark markings. They thought at 
first that the Moon merely served as a huge 
mirror in which to reflect the rough contours of 



MOON, DAUGHTER OF EARTH 129 

the Earth. Indeed, even now, those who know 
little about astronomy often fancy they see the 
outlines of Europe, Asia, and Africa on the 
bright face of the moon. One may find out 
many things about our satellite just by watching 
it with the naked eye. One of the best tests 
of the eyesight is to be able to detect the great 
plain called Grimaldi. It is a dark oval spot, 
containing some 14,000 square miles, so astron- 
omers say, and there are huge mountains flank- 
ing it on the sides. By the aid of a small glass, 
the field of the Moon is made much more inter- 
esting. One of the most fascinating phenomena 
is to be seen when the Moon passes over, or 
occults a star, causing it to disappear instan- 
taneously. 

Long ago the Moon was the best means the 
travelers had for reckoning time at night. At 
full Moon the orb is due directly south at mid- 
night. Every night before the Moon is full 
one must subtract fifty -five minutes ; that is one 
night before full moon it is due south at 11:05 
p. m ; two nights before full moon it will be due 
south at 10:10 p. m. After the Moon is full it 
will be due south fifty-five minutes later, that is 



130 MOON, DAUGHTER OF EARTH 

one day after full moon the orb is due south at 
12 :55, and so on. To-day the Moon is of such 
immense importance to navigators that many 
astronomers are needed to keep accurate record 
of her movements. It is the attraction of the 
Moon for the Earth that produces the tides. 
The hours for "high" and "low" tides are care- 
fully computed by the astronomers and form a 
very necessary part of the nautical calendars. 
The Sun has some little influence on the tides, 
too, and when the Sun and the Moon are in line, 
as at full and new Moon, the tides are highest. 
We call these spring tides. At half -moon, the 
Sun and the Moon are exercising a pull in op- 
posite directions. Then the tides are the lowest. 
Such tides are called neap tides. The tides are 
Nature's scavengers of the sea coast. Without 
their energetic scrubbing and cleansing, ris- 
ing twice in every day and night, our beaches 
would be far from the spots of delightful fresh- 
ness that they now are. 

Suppose that we might be able to hail a pass- 
ing comet and hie ourselves off to the Moon: 
what would we really find there? We should 
have to carry air with us, or we could not pos.- 



MOON, DAUGHTER OF EARTH 131 

sibly live even to reach the Moon, much less get 
our breath after we got there. At the height 
of three or four miles above the Earth, the atmos- 
phere grows very thin, and at ten miles up, 
unless we had life-giving oxygen with us at com- 
mand, we should die. It might also be a good 
plan to have water with us. But we won't 
bother with these essential details. Just sup- 
pose the problem solved and ourselves landed 
on the Moon. Will we dare set foot on the 
rocks? No doubt they are unspeakably cold, 
all about is freezing. There is a possibility 
that we may turn immediately to pillars of ice! 
There is no air-blanket to hold the heat from the 
Sun, so that luminary is of no possible use, so 
far as heat is concerned. Astronomers have 
determined that during the long lunar nights 
the temperature must drop to 300 degrees or 
more below zero. We shall certainly stay but 
a moment! 

How extraordinarily light we feel! And 
with reason: for objects on the Moon weigh only 
one-sixth what they do on Earth. We scarcely 
feel the weight of our big silver watch, as we 
draw it out to see the time. A stone that we 



132 MOON, DAUGHTER OF EARTH 

could not possibly lift at home is picked up 
without the slightest effort. And as we step 
hastily off to have a look around, we stop in 
amaze, for it is as though we had donned the 
Seven League Boots! One of our party mo- 
tions us to try a jump; but we are not to be 
tempted. We feel very sure we could vault 
that great rock yonder without half trying. 
Indeed, more than likely we should land away 
over in Copernicus or — or Archimedes! Of 
course, no one makes any attempt to talk. For 
as there is no air here to carry the waves of sound, 
we could not possibly be heard. Also we are 
careful to stand in the direct sunlight. Indeed 
we hardly dare to look into the shadows. They 
are deeper and blacker than anything that could 
possibly be imagined on the Earth. We feel 
sure that if we should step off into one, we should 
be as certainly lost as if we had fallen into one 
of the deep pits. We should be invisible to our 
comrades, and whistling or shouting would not 
avail. 

Our attention is attracted to the wide Uni- 
verse. Comparatively close to us is a moon, 




THE MOON: THIRD DAT 




THE MOON— REGION OF CLAVIS AND TYCHO 



MOON, DAUGHTER OF EARTH 133 

about four times as broad as the satellite we are 
used to gazing upon. It has wonderful polar 
caps of ice and snow, vast oceans, mountains and 
plains, and great hazy cloud areas. Somehow, 
there is a very familiar look about its general 
outlines! Can it be that this wondrous moon 
is our earth? Yes, indeed. If we were to stay 
long enough, we should see it turn on its axis 
every twenty four hours and run through all its 
phases from crescent, quarter, gibbous, and full 
back to crescent again, just as we see our own 
Moon doing when we are at home. Millions of 
miles out in space is the Sun, and because of the 
absence of air, we see the great orb of day in all 
his wondrous magnificence, — sunspots, fiery 
prominences and marvelous corona, all in daz- 
zling array. What an unspeakably gorgeous 
spectacle ! The stars, too, seem much bigger and 
brighter than they do from the Earth, and there 
are many more of them — as many as we see at 
home when looking through a three-inch tel- 
escope. 

But, notwithstanding all these outward splen- 
dors, it is a relief to embark from this cold, dead 



134 MOON, DAUGHTER OF EARTH 

world, with its endless succession of jagged 
rocks, great gray barren plains, and extinct 
volcanoes — this tomb rolling onward through 
space. 



VI 

COMETS, OR THE GHOSTS OF SPACE 

The name comet comes from the Greek word 
hair 3 these ancient people having styled the 
comet as a hairy star, because of its long lumin- 
ous tail streaming out like a bright veil of wo- 
man's hair. For generations the comet was 
everywhere looked upon as a harbinger of great 
tidings. Early preachers taught that it was 
composed of the sins of mortals, which, ascend- 
ing to the sky, were set on fire by the wrath 6% 
God. Copernicus scoffed at this doctrine ; Kep- 
ler claimed that the comets originated, ran their 
course, and died; other early astronomers, too, 
did their best to show that as the comets were 
superlunar — that is beyond the Moon — they 
could not be intimately concerned with war, 
pestilence, or famine. But the ignorant multi- 
tude gave these assurances small heed. The 
downfall of Nero was supposedly heralded by a 

135 



136 COMETS 

comet; in the time of the Norman Conquest, a 
comet appeared spreading its glorious tail across 
the sky, a forerunner, it appeared, of the subse- 
quent victory of the Normans. Another comet, 
seen in 1456, supposedly had a connection with 
the capture of Constantinople by the Turks. 
As late as the seventeenth century, an illness 
among the cats in Germany was ascribed to the 
appearance of a particularly freakish comet. 

But as science became more advanced, and 
telescopes more numerous, it was found that for 
one comet seen by mortal eyes there were hun- 
dreds which could only be seen through the glass. 
Obviously, then, the old theory would have to 
be abandoned. But whence came these capri- 
cious visitors of space? It was easy to believe 
that they might have been drawn by the attrac- 
tion of the sun. But what kept them from 
tumbling into the shining orb, and whither did 
they go? It was Newton who first declared 
that comets moved in orbits, just as the planets 
do, and subsequently a great deal was discovered 
about these erratic messengers of space. 

To begin with, it was found that a comet is 



COMETS 137 

really made up of three parts: (1) a bright 
head or core, called a nucleus; (2) a hazy light 
layer, called a coma; (3) a luminous tail, which 
waxes and wanes in a most remarkable manner. 
Moreover, by means of the spectrum, the very 
substances which make up the nucleus, the active 
part of the comet, have been determined. Chief 
among these are iron, carbon, sodium, — all mate- 
rials that are found in the Sun and the planets, 
and materials with which we are all familiar. 
Sodium perhaps you may not recognize; but it 
makes up the bulk of the salt in the sea. These 
materials appear in the comet in bunches of 
stones, which are held together as they speed 
through space by that wonderful agent known 
as attraction. As a comet draws near to the 
Sun its elements begin to get hot and to throw 
off burning vapors or gases, which make up its 
coma, and then stream off in luminous vapors 
forming its tail. 

A comet without a tail is a very poor affair, 
and astronomers give it small heed. But one 
cannot always tell about comets. When first 
sighted heading toward the Sun, a comet has no 



138 COMETS 

tail worth noting. Astronomers, however, keep 
it covered. They know that if the comet is not 
a poor burned-out affair, there are likely to be 
marvelous effects as soon as the Sun's heat be- 
gins to be felt. If the tail does begin to develop, 
it shoots out from the head with enormous rapid- 
ity, and often grows to many million miles in 
length as the comet comes on with terrific speed. 
Once the messenger has made his obeisance to 
the Sun, however, and headed the other way the 
tail begins to diminish, and presently the comet 
vanishes into space as undecorated as when it 
was first heralded. 

Comets have been known with two, three, and 
as many as six tails. The comet of 1882 whose 
wonders astronomers never tire of relating, had 
a marvelous tail 100,000,000 miles in length. 
Could this comet's head have been placed at the 
Sun, its tail would have streamed not only to 
the Earth, but out into space across it! Natur- 
ally one would expect a comet's tail to follow its 
head. It does, so long as the comet is rushing 
toward the Sun, but when it turns to go the 
other way, the tail sweeps on in advance. Thus, 
you see, a comet's tail always points away from 



COMETS 139 

the Sun. "Why?" queried the astronomers. 
But it was many years before the real reason 
was discovered. Now we know that the Sun 
not only attracts comets but that his light 
exercises a pushing or repulsive power on 
minute particles. Just what this repellent 
power is has caused much argument. Some 
scientists say that it is electrical; others that it 
may be due to what is called light pressure. At 
any rate, we know that it only affects the very 
smallest, most insignificant particles of matter. 
The planets and moons are in nowise troubled. 
This pressure, then, or repellent force, whatever 
its nature, drives back the tiny vaporous par- 
ticles which make up the tail, causing it always 
to point away from the Sun. It is this pressure, 
too, which is believed to make up the seeming 
number of tails. As we have seen, a comet's 
nucleus is composed of certain elements. The 
vaporous particles of these elements, no doubt, 
have different densities. Consequently the 
repellent power of the Sun affects these un- 
equally, thrusting the diverse elements out at 
different angles, so that one tail may be due to 
iron vapor, another to sodium, and so on, 



140 COMETS 

It happens that there are other bodies in the 
sky very like comets ; we call them nebulae. So 
that just as a planet is liable to be mistaken for 
a star, so a comet is liable to be termed a nebula. 
It chances also that the test in the two instances 
is the same. A nebula always stays in the same 
place, like a star, while the comets and planets 
are ever on the move. There are several ways 
to distinguish a comet from a planet. In the 
first place, it must be remembered that the 
majority of comets are to be seen only through 
the telescope ; the really brilliant comets that can 
be seen in a lifetime may be counted on the 
fingers. Again, comets never burst into view, 
wondrous and beautiful; no matter how great 
they may grow to be, they are first seen as dim 
little patches of light. They travel with exceed- 
ing switfness. Indeed, by watching one steadily 
for a time it may be seen to slip past the stars 
it is first noted among. Each night, too, an 
approaching comet grows larger and brighter, 
and its tail presently begins to make its ap- 
pearance. When it reaches this stage, the comet 
is more wonderful observed with the naked eye 



COMETS 141 

than through the most powerful telescope. Its 
head glows brighter than the brightest planet, 
and its tail spreads out in a glowing arc which 
lights up the whole heavens. The planets, you 
remember, are not found outside the zodiac. 
The comets shoot in and out of the solar system 
from and to every direction, in apparently the 
most erratic and method-mad fashion. 

They are the witches of the sky, fantastic and 
changeable. We can almost fancy that we see 
the broomsticks ! But staid astronomers are not 
at all in love with their antics. How many pages 
of painful figures have they wrecked! Here is 
an orbit and schedule carefully worked out. 
Miss Comet is due to make her bow at such and 
such a time. The fact is published. But she 
does not appear. Then, when least expected, 
along she may whisk, taking the world by sur- 
prise — and the astronomers with the rest. 

The nearer a comet gets to the Sun the faster 
it travels, frequently rushing along more than 
a thousand times swifter than the speed of a rifle 
ball. One case is on record of a comet which 
had been coming in for an incalculable time 



142 COMETS 

toward the sun, suddenly being drawn forward 
at such a tremendous rate that in two hours it 
had speeded round the Great King and started 
back into the depths. Of course, these terrific 
outbursts do not last long. "A pace which near 
the sun is 20,000 times that of our express trains 
diminishes,' ' we are told, "to 10,000 times, to 
fifty times, to ten times that pace; while in 
the outermost part of its path the comet seems to 
creep along so slowly that we might think it 
had been fatigued by its previous exertions." 

An old astronomer calculated that there were 
probably more comets in the sky than fishes in 
the sea. To date, however, only about 1,000 
comets have been registered. To be observed, 
it has been estimated, that a comet's head must 
be at least 15,000 miles in diameter. The aver- 
age is from 25,000 to 100,000 miles, and the 
greatest comet yet recorded is that of 1811, 
measuring over 1,000,000 miles — fourteen times 
larger than Jupiter, the largest planet! 

Where these strange visitors, these ghosts of 
the skies, come from, and the paths that they 
travel — for there is really order in their wild on- 
rush — is one of the most interesting problems of 



COMETS 143 

astronomy. Suppose there should be at this 
moment, drifting thousands of miles out in space, 
a torpid bit of the novel material of which comets 
are made. The ever-reaching beams of the Sun, 
even at this vast distance, make themselves felt. 
And presently the little loiterer finds itself stirred 
to the depths. Lazily it rouses up and begins 
slowly to answer the impelling invitation. Its 
movement is only slightly increased yet, it may 
be centuries, a thousand, ten thousand years be- 
fore it reaches the solar system; then its speed 
will rise prodigiously, growing ever faster as it 
draws nearer until, by and by, it has paid trib- 
ute to the Great Ruler and dashed onward in its 
career. 

If it is the Sun that has called the comet, why 
does it not dash straight into his alluring beams ? 
For one reason, because it had a motion of its 
own before the Sun's attraction was felt, and 
according to the laws of motion it is impelled 
to follow its own course. But surely if the 
attraction of the Sun is strong enough to call 
the comet such a vast distance, it ought to be 
able to hold the visitor when it arrives. Yes, 
but consider: the comet dashes up at a speed 



1U COMETS 

20,000 times faster than the fastest express 
train. Moreover, the comet is several thousand 
miles away from the sun; the swift-traveling 
comet previously mentioned, which went by at 
perihelion at the amazing rate of 366 miles per 
second, passing around the Sun in two hours, 
made the nearest known approach to the great 
orb — 30,000 miles. The Sun does not stop a 
comet, but it changes its direction. 

Three forms of path are possible to comets. 
What these are may best be gleaned from the 
illustration. Only those comets which follow 
the elliptic path can be considered members of the 
solar system. The other two paths are open 
curves, and once the comet has swung in and paid 
his ghostly cometary tribute, he will never come 
back. There is one caution, however: Astron- 
omers have found that these two latter curves 
may sometimes be in reality gigantic ellipses, 
and that in the course of a thousand years or 
more the wanderers along these paths may heave 
into sight again. Of course there must be some 
method of determining this, and presently the 
mathematicians proved that when a comet going 



COMETS 145 

at a speed exceeding twenty-six miles per second 
is traveling an orbit distant ninety-three million 
miles from the Sun it will never come back. 
Very often the velocity of a comet is so near 
this figure, that astronomers are in doubt con- 
cerning its return. 

At nearly every observatory there are scouts 
detailed to watch for comets. Immediately one 
is sighted, it is at once charted, and investigations 
commence to see whether it is a known or an 
unknown visitor. And here no end of complica- 
tions may arise ! In the case of the planets and 
asteroids, certain drawings and specifications, 
and above all photographs, help to establish iden- 
tity. But not so with the comets. Their shape 
and size may vary with each and every appear- 
ance. Now one will have a long straight tail; 
again a short fan-like appendage ; again a forked 
tail, or none at all. The "looks" of a comet, 
therefore, are no aid at all in identifying it. The 
more certain way to do so is to trace its pathway 
through the heavens — and even that is not cer- 
tain; for it frequently happens that during its 
erratic wanderings it comes in contact, or nearly 



146 COMETS 

so, with other heavenly bodies, and is hurled mil- 
lions of miles out of its beaten path. Sometimes 
it loses its way altogether. Again it may be 
shattered into several fragments. Astronomers 
have frequently noted two or three such wander- 
ers along the general path that one known comet 
was supposed to take. Then the question arises 
as to whether they are new bodies, or merely sec- 
tions of the old one widely scattered. 

About thirty comets in good and regular stand- 
ing are now known, with periods of less than 
100 years, the shortest being Encke's comet, 
three and one-half years, and the longest that 
of Halley's comet, something over seventy-five 
years. Nearly all of these bodies are invisible 
to the naked eye, and at best can only be seen 
for a very brief period. The outer planets all 
have comets which revolve in elliptical orbits 
about them: Jupiter 18, Saturn 2, Uranus 3, 
and Neptune 6. And the interesting part about 
this feature is that these comets are captives : once 
they undoubtedly described great parabolas or 
hyperbolas. But in rushing toward the Sun, 
they passed so near the planet to which they now 



COMETS 147 

owe allegiance that their paths were deflected, 
and they found themselves held forever by 
the overmastering attraction of the giant 
bodies. 

Generally speaking, the great comets come 
within our vision once and are then never seen 
again. Halley's comet is an exception, and this 
comet is also of special interest because it was 
by means of it that the world first became as- 
sured that comets really traveled in orbits. 
Halley, the English astronomer, who first sighted 
this comet and charted its ellipse, found that it 
came very near the Sun in one part of its jour- 
ney and swung out nearly to the orbit of Neptune 
on the other. In poring over the records to see 
if he had found a new comet, he noted that twice 
before, at intervals of around seventy-five years, 
messengers of space had been charted in almost 
this same orbit. Most carefully Halley con- 
sidered the matter: he knew that, from its 
proximity to Jupiter and to Saturn at certain 
points, the path of his comet was bound to be a 
trifle uncertain at each revolution. And a great 
idea came to him: he became assured that his 



US COMETS 

comet and the other two which had been recorded 
were one and the same. If this were true, it 
fully established Newton's theory that comets 
had orbits. But Halley was a man in his prime. 
He knew he would not live another seventy-five 
years to see his belief proven. So he published 
his theory, adding: "If it should return accord- 
ing to our predictions, about the year 1758, im- 
partial posterity will not refuse to acknowledge 
that this was first discovered by an Englishman." 
The name the comet bears fully shows that 
posterity, after verifying the truth of H alley's 
prophecy, was only too glad to perpetuate his 
fame. Incidentally, as a further witness of the 
accuracy of mathematician's figures, three cal- 
culators set the date for the return of the comet 
as November 4, November 11, and November 
12, 1835, respectively; the comet appeared 
November 15. Halley' s is the comet previously 
mentioned as appearing in the time of the 
Norman conquest, 1066. It is pictured in the 
celebrated Bayeux tapestry. The opening lines 
of Tennyson's Harold also portray this far- 
famed comet: 



COMETS 



149 



Firsi Courtier. 



Second Courtier. 
First Courtier. 

Third Courtier. 



Second Courtier. 
First Courtier. 
Aldwyth. 
Gamel. 



"Lo! there once more — this is the 

seventh night! 
Yon grimly-glaring, treble-brandish'd 

scourge of England! 
"Horrible ! 

"Look you, there's a star 
That dances in it as mad with agony! 
"Ay, like a spirit in hell who skips and 

flies to right and left, and cannot 

scape the flame. 
"Steam'd upward from the undescend- 

ible Abysm. 
"Or floated downward from the throne 

of God Almighty. 
"Gamel, son of Orm, what thinkest thou 

this means? 
"War, my dear lady!" 



The question arises: Is there any danger of 
the Earth colliding with a comet? Since comets 
have a reckless habit of dashing into the solar 
system at any time and from any direction, it 
is quite conceivable that such an occurence might 
be possible. However, astronomers have fig- 
ured that but one collision of this nature is likely 
to take place in a space of 15,000,000 years! 
"If one should shut his eyes and fire a gun at 
random in the air," we are told, "the chance of 
bringing down a bird would be better than that 



150 COMETS 

of a comet of any kind striking the Earth." 
More than once the Earth has been known to 
pass through the tail of a comet, and in each 
instance few besides the astronomers were aware 
of the event. In June, 1861, a brilliant comet 
appeared between the Earth and the Sun, about 
14,000,000 miles from our planet, while its tail 
stretched way beyond us. All day the heavens 
had a yellowish tinge like that of early dawn, 
and the Sun shone feebly, though the sky was 
cloudless. At seven o'clock dusk came on, and 
lamps had to be lighted. Now, too, a golden- 
yellow disc, half -hidden in a filmy veil, appeared 
in the sky — evidently the Sun's rays had pre- 
vented its being seen earlier. This was sup- 
posedly the comet's head. A witness described 
it as "though a number of light, hazy clouds were 
floating around a miniature full moon." The 
tail of the comet floated out and away above it 
like a cone of light, and when the head had disap- 
peared below the horizon, the end of the tail had 
just reached zenith. Nor was this all. Strange 
shafts of light seemed to hang straight above 
the Earth. L We seemed to look up through a 



COMETS 151 

haze, and it was believed the Earth was actually 
enfolded in a second tail of the comet. No one, 
however, felt any discomfort. 

It is probable that our atmosphere, thin as 
it is, would seem like a blanket in comparison 
with the vaporous particles which make up a 
comet's tail. The orbits of certain comets lie 
very close to some of the planets, but they seem 
to exercise no influence whatever on the plan- 
etary bodies. An instance is recorded of a 
comet coming so near Jupiter that it was act- 
ually among his moons. The comet was so up- 
set that he was pulled right out of his old path 
and set going in a new one. But Jupiter and 
his satellites showed not the slightest inclin- 
ation of being aware of the stranger's presence. 

Some astronomers think that direful results 
might occur should we have a head-on collision 
with a comet. All agree that probably the air 
and water would be instantly consumed and dis- 
sipated, and a considerable region of the Earth's 
surface raised to incandescence. But yet an- 
other consequence equally malign to human in- 
terests is foreseen by Professor Todd, who 



152 COMETS 

points out that, in the much more probable event 
of an encounter of the Earth's atmosphere with 
huge chunks of a large hydrocarbon comet, nox- 
ious gases might be diffused in such volume as to 
render the atmosphere unfit for breathing, and 
in this way bring death to all forms of animal 
life. 

Comets seem to feel the same fascination for 
the Sun that moths do for the candle, and those 
ghosts of the skies which travel in elliptical paths 
go on wheeling round and round the Ruler of 
Light like so many gigantic moths. As for 
those which come in upon the vast parabolas and 
hyperbolas to pay homage to our Sun, perchance 
these may make the same obeisance to other 
suns throughout the stellar space. Certain it 
is we never see them again, but we know that, 
like the solar comets, their moth-like fascination 
for heat and light must at length prove their 
undoing. For, as a comet approaches the sun 
time after time "to be invigorated by a good 
roasting," it must of necessity throw off a good 
deal of its bulk in the process of tail-making. 
As it has no possible means of renewing these 



COMETS 153 

spent materials, it follows that the comet must 
certainly reduce itself to a considerable degree 
at each revolution. The tails, therefore, must 
decline in size and magnificence. And by and 
by the tail-making substances having all burned 
away, we have that sorry spectacle a comet with- 
out a tail. We know to a surety that this is 
exactly what happens. Moreover we have on 
record proofs of the further disintegration of the 
comet. Certain comets now travel tandem. 
It is known that these are the three parts of what 
was once one huge comet. Other comets have 
been so broken up that they now make the jour- 
ney in groups; and in still other cases, final 
obliteration has so nearly been reached that the 
comet has literally gone to pieces, existing only 
in a shower of small stones and fragmentary 
matter. 

In 1832, the world generally had what has 
since been designated as a "comet scare." Cal- 
culators had shown that Biela's comet, which 
regularly made its pilgrimage to the Sun in a 
period between six and seven years, was due to 
sweep over the Earth's orbit. And considerable 



154 COMETS 

uneasiness was felt lest the world might be 
wrecked! In Paris, a regular panic ensued, 
which was quelled only when the director of the 
observatory issued a pamphlet explaining the 
true situation and showing that the comet in its 
nearest approach to the earth would be at a 
distance of 50,000,000 miles. Of course, noth- 
ing resulted from the appearance of the dreaded 
ghost! On its next circuit it was not seen, and 
by the time it was due to appear again almost 
everybody but the astronomers had forgotten 
about Biela's comet. They, however, were on 
the watch, and presently the comet was de- 
tected coming on in what seemed a curious pear- 
shape. All the telescopes were brought to bear 
upon it, and as the ghostly messenger drew 
nearer it was seen that the comet had actually 
divided into two portions. Long before, astron- 
omers had established the theory of the life of 
comets, but this was the first proof actually ac- 
corded to support their belief that the comets 
began to wane by subdivision. 

You may well imagine how eagerly the next 
appearance of Biela's comet was awaited in 



COMETS 155 

astronomical circles! This time the two comets 
were again witnessed, but the companion comet 
was now far behind its primary. Indeed, it was 
coming on so half-heartedly that a million and a 
quarter miles lay between them! At the next 
period for return, Biela's comet was unseen, but 
no one took the matter seriously, for it was so un- 
favorably placed that detection was very un- 
certain. The next period, however, was sup- 
posed to show the comet up unusually well. 
Everybody got ready for the visitor, but it failed 
to appear. The astronomers concluded that it 
had gone to pieces somewhere out in the vast 
reaches of space, and no one ever ex- 
pected to hear anything more concerning Biela's 
comet. 

At its next period, however, in 1872, an 
extraordinary thing happened. To be sure no 
one saw anything of the comet, but on the night of 
November 27, when the earth crossed the trail of 
the lost one, there was a magnificent shower of 
shooting stars. Here was the final proof for the 
men of science! For over five hours the earth 
ploughed its way through the wreckage of the 



156 COMETS 

lost comet. The "rain of fire" was magnificent. 
Four hundred meteors fell in the small span of 
a minute and a half; and fire-balls, here and 
there, apparently as large as the Moon, were ob- 
served. At this time, too, a large iron meteorite 
fell, and was picked up in Mexico. This may 
or may not have once formed part of the doomed 
comet. 

Sweeping the heavens for comets is an inter- 
esting occupation; and the heaviest outlay is 
in patience and perseverance. Messier, a large 
discoverer of comets, found all of his with a very 
ordinary glass, magnifying only five times. 
Pons, the most successful of all comet-hunters, 
who has no less than thirty to his credit, began 
his search while holding the humble position of 
doorkeeper at the observatory at Marseilles. 
To-day his name outranks that of the director 
who kindly taught and encouraged him. 

The residue of comets, minute objects, so small 
that you might carry one in your pocket, if 
you could pick it up, forms an interesting sub- 
ject by itself. For these bunches of comet chips, 
which you may perhaps have regarded as mere 



COMETS 157 

rubbish in the great workshop of the skies, have 
yet another cycle in the marvelous Universe. 
We shall read about this in the chapter "Shoot- 
ing Stars." 



VII 

THE NEBULAE, OR FIRE MIST 

No more remarkable objects are to be seen in 
the heavens than the hazy celestial clouds known 
as nebulaa, or fire mist. Likewise, too, they are 
of the utmost interest, for they give us a clew 
to the very beginning of the Universe. It is 
believed that the nebula? are the star factories 
from which come suns and the planets and their 
satellites. 

Early astronomers found the nebulas most 
puzzling. At first it was the general opinion 
that these "little clouds," as the term nebuUe 
means, were all star clusters too far away to be 
seen separately. Herschel, however, advanced 
the theory that the clouds of nebulous light were 
not stars, but were made up of huge masses of 
glowing gas. The invention of the spectroscope 
proved the truth of this supposition, and showed, 
moreover, the elements involved. Hydrogen 
makes up the largest part; helium has recently 

158 




THE GREAT NEBULA IN ORION 




THE GREAT NEBULA IN ANDROMEDA 



NEBULA, OR FIRE MIST 159 

been added, and there are other substances not 
yet recognized on the earth. 

Two of the most famous nebulae in the heavens 
may be observed with the unaided eye. The 
greatest of these is to be seen in the constellation 
of Orion, in the winter skies. Some clear night, 
by looking closely, you will observe that the 
middle star of the "sword" seems somewhat hazy. 
Looked at through a small hand telescope, this 
haziness develops into a considerable cloud 
against the dark background of the sky. Seen 
through a large instrument, it becomes a wonder- 
ful, wide-spreading nebula, with bright and 
dark channels, and "extensive wisps of nebulos- 
ity" reaching out in many directions, involving 
other stars. A curious opening, or break in the 
light, at one side has given it the name of the 
Fish-mouth Nebula. Another interesting point 
about the Great Nebula in Orion is that the star 
which we note with the naked eye resolves under 
the telescope into not one but twelve stars of 
various size. Similarly a keen eye will pick out 
a hazy spot in the constellation of Andromeda, 
which even the smallest telescopic power resolves 
into a great nebula. This nebula is much less 



160 NEBULA, OR FIRE MIST 

wide-spread tharj that m Orion. Though its 
distance from the solar system is very great, its 
diameter has been sufficiently calculated to make 
certain that a great many years would be re- 
quired even for light to pass from one side of 
the nebula to the other. It has been estimated 
that if a map of the Great Nebula in Androm- 
eda could be made, a map of the solar system, 
drawn to scale, would seem a mere speck if laid 
upon it. 

The known nebulse in the heavens reach up- 
wards of 500,000. Many of these, of course, 
are so small, or at such a great distance, that 
they are only within photographic reach of the 
great reflecting telescopes such as the marvelous 
instruments employed at the Mt. Wilson Solar 
Observatory, near Los Angeles, California. 
Nebulse are of all shapes and sizes. To quote 
a recent English writer, "We have some, like 
brushes, others resembling fans, rings, spindles, 
keyholes; others like animals — a fish, a crab, an 
owl, and so on; but these suggestions are imag- 
inative, and have nothing to do with the real 
problem." In the System of the Stars Miss 
Clerke says: "In regarding these singular 



NEBULA, OR FIRE MIST 161 

structures we seem to see surges and spray- 
flakes of a nebulous ocean, bewitched into sud- 
den immobility; or a rack of tempest-driven 
clouds hanging in the sky, momentarily await- 
ing the transforming violence of a fresh onset. 
Sometimes continents of pale light are separated 
by narrow straits of comparative darkness; else- 
where obscure spaces are hemmed in by luminous 
inlets and channels." 

For convenience in classification, astronomers 
divide the nebulae into six classes, based on their 
various forms: (1) annular nebulas, (2) elliptic 
nebulas, (S) spiral nebulas, (4) planetary ne- 
bulas, (5) nebulous stars, (6) irregular nebulas, 
for the most part very large. "If it be realized," 
says Chambers, "that the word 'annular' is de- 
rived from the Latin word anmdus, a ring, a 
ready clue will be had as to the general form of 
the first type of nebulas." In the constellation 
of Lyra may be seen, under telescopic power, 
one of the most marvelous of these gigantic rings 
of luminous gas. To judge of the size of this 
ring, Ball tells us that a train, starting from one 
side of this nebula, and traveling 60 miles an 
hour, might rush on for a thousand years with 



162 NEBULA, OR FIRE MIST 

unabated speed and then most certainly the 
journey across this vast immensity would not 
have ended. "Nor do I venture to say," he 
continues, "what ages must elapse ere the ter- 
minus at the other side of the ring nebula would 
be reached." The Great Nebula in Andromeda, 
is a specimen of elliptic nebula?. "Apparently," 
says one authority, "it is composed of a number 
of partially distinct rings, with knots of condens- 
ing nebulosity, as if companion stars in the mak- 
ing. Its spectrum shows that it is not gaseous, 
still no telescope has yet proved competent to 
resolve it." Spiral nebula? show such wonderful 
whorls of nebulosity that they are frequently 
called "whirlpool nebula?," and this term seems 
to describe them fittingly. They are stellar in 
character, that is like the stars. Their substances 
are intermingled — gases, liquids and solids. 
Planetary nebula? are so called because they show 
a roundish disc, like the large planets, only 
much fainter. They are mostly gaseous in com- 
position. Nebulous stars are those hidden in 
luminous fog. Most of these can be seen only 
through the telescope. 

It is as impossible to measure the distance of 



NEBULA, OR FIRE MIST 163 

the nebulas from the Earth, as it is to determine 
their size. We only know that they are as far 
away at least as the stars. Nor can we form 
any definite idea as to what a close-up view 
would be like. "We can say that the planets 
are globes like the Earth, with days, nights, sea- 
sons, and years," says Macpherson; "We can as- 
sert that the stars are suns, like our sun, probably 
with planets revolving round them; we can even 
form some idea of what the scene must be at the 
center of a star cluster ; but in the case of a neb- 
ula our imagination fails. Their immense size, 
their enormous distance from our system, and the 
mighty changes which are believed to be in 
progress in their midst, show us in a new light 
the insignificance of the Earth, and increase 
our astonishment when we remember that only 
three hundred years ago our little planet was be- 
lieved to be the center of the Universe." 

Another interesting theory is that the nebulas 
are the residue of materials of original chaos, 
from which our solar system and many other 
such systems as well have been evolved. Cer- 
tain of the elements found in the Earth are dis- 
cernible. Those nebulas which show greenish 



164 NEBULAE, OR FIRE MIST 

in color are largely of hydrogen gas. A few 
of the white ones are resolvable in the high 
power telescopes into masses of separate stars. 
For this reason, it was believed in the beginning 
that all the nebulas could thus be resolved if only 
enough telescopic power could be secured. 

Strangely enough, the nebulae seem to be the 
most numerous in that part of the heavens where 
there are the fewest stars. It has been found, 
too, that these vast luminous masses are moving 
through the heavens at a speed about equal to 
those of the stars. The bright nebula in Draco, 
for example, seems coming in towards the Earth 
at the rate of forty miles per second. On the 
other hand, the Orion nebula is receding at the 
rate of eleven miles each second. As yet none 
of the nebulas have been discovered to have any 
axial motion. 

There are many difficulties, however, in the 
way of obtaining accurate details concerning ob- 
jects so indistinct and remote. Swift as light 
travels, its rays require at least a thousand years 
to bring their message from that far-off mass. 
If at the time of the Norman Conquest of Eng- 
land, the starry clusters of Orion had grown dim, 



NEBULA, OR FIRE MIST 165 

we should but now be finding it out. Through 
the centuries their diffused light would have per- 
sisted like wraiths. 

To explain how the stars (the suns of space), 
and the planets, as well, have been formed, two 
theories have been advanced, and although these 
differ in many respects, both begin with the 
nebulas. In the first of these, called the nebular 
hypothesis, the idea is that once, far back many 
hundreds of millions of years ago, all the matter 
that now makes up the Universe was scattered 
very thinly through the unlimited vastness of ce- 
lestial space. Then, as now, the particles of mat- 
ter attracted one another according to Newton's 
well established laws. Presently centers of 
attraction were formed, and these centers 
drew unto themselves other particles of matter. 
Thus by the inward falling of matter, and the 
friction caused by the collision of particles, heat 
was formed, and the material masses grew into 
vast nebulae, which filled all the heavens with 
luminous fire mist. Millions of years passed, 
and still the process went on, until finally great 
nebular whirlpools were set in motion, and began 
revolving with inconceivable swiftness on their 



166 NEBULAE, OR FIRE MIST 

axes. The temperature rose terrifically at 
centers where condensation became greatest, 
and presently vast numbers of suns were formed. 
What followed next we have determined only 
so far as our own sun is concerned, but there is 
every reason to suppose that other suns may have 
developed solar systems by reason of their im- 
mense centrifugal force sloughing off great rings 
of nebulosity which later formed planets, and 
these in turn their satellites, just as is supposed 
to have been the case in our own instance, as we 
have already seen. To be sure, we must bear 
in mind that all this is merely an hypothesis — 
that is, a theory. It has never been altogether 
proved, nor is it likely that it ever will be. How- 
ever, many great minds have contributed to this 
theory, and it is the one most universally accepted 
to account for the scientific development of the 
Universe. Recent astronomers, however, find 
this theory still open to serious objections. 

The second theory, and more recent one, is 
known as the Planetesimal Hypothesis. This 
begins with some remote ancestor of our solar 
system, a more or less condensed central sun, 
having a slow rotation and surrounded by a vast 




AN IRREGULAR NEBULA IN CTGNUS 



NEBULAE, OR FIRE MIST 167 

swarm of planetoids. All these tiny bodies 
followed an elliptical path around their sun. 
The swirling masses seen in the spiral nebulae 
to-day are apparently of this type. Now let us 
see what next happened — if this theory is 
correct. Out of this great central mass our own 
sun slowly developed, its body being increased 
by many of the near-by particles adhering to it, 
or falling in upon it. Meanwhile, the whirling 
nebulae continued to sweep up outlying particles 
and throw them into globular shape — until they 
became the planets which in their turn whirled 
about the Sun. Still smaller particles were 
swept up and molded into the satellites of the 
planets, such as our Moon. 

The more we reflect on the marvelous wonders 
and performances of the nebulse, the more 
boundless and deathless our Universe becomes. 
We have gone far in the three hundred years of 
patiently figuring out our own position in the 
heavens, but unquestionably we are only on the 
threshold of the miracles yet to be discerned. 
There are evidences going to show that our own 
solar system was once a nebulous mass cool and 
dark, widely scattered, and revolving but slowly. 



168 NEBULA, OR FIRE MIST 

Even now the vast spaces of sky may conceal 
many such masses. Since they do not glow with 
light we have no means of locating them. We 
can but speculate. Likewise, too, many of 
the most familiar nebulse have grown several 
times brighter in the years they have been under 
observation. When we consider that these lat- 
ter enormous masses of gas, many, many times 
the area of our own solar system, are sailing on 
in an endless journey through infinite space, just 
as the stars and comets are, we can but bow in 
reverence and awe before the Mighty Intelli- 
gence whose hand is on the helm and who alone 
can answer the queries Wherefore? and Whith- 
er? 






VIII 

SHOOTING STARS 

"Look! Yonder goes a shooting star!" How 
often we have all heard this exclamation, and fol- 
lowed with momentary interest the little flash of 
burning sparks which darts along the heavens to 
disappear in the blackness of space! Perchance, 
too, we took the incident entirely as a matter of 
course, giving no heed whatever to the fact that a 
really, truly star could not "shoot" in this re- 
markable manner. The stars are suns. They 
are "fixed" at enormous distances from the 
Earth, while the phenomenon that we call a 
shooting star is discharged a few miles above the 
surface of our planet. Obviously, then, the 
terms shooting star and falling star are mislead- 
ing and altogether incorrect; what we really see 
is a meteor, or a bolide, as some astronomers 
term it. 

Almost any casual observation of the clear 
night-time sky will be rewarded by the glimpse 

169 



170 SHOOTING STARS 

of one or more meteors. We should witness the 
same phenomena during the day, also, were it 
not for the sunlight. It has been estimated that 
the dust of 400,000,000 meteors falls to the Earth 
every twenty-four hours, having a weight col- 
lectively of no less than 400 tons. At this rate, 
it will be seen that the mass of the Earth must 
gradually be growing larger. Not very notice- 
ably in the course of a year perhaps ; but "every 
little makes a mickle." Our Earth has been 
hoarding up meteor dust since the beginning of 
Time. Ages and ages ago it may have been 
much smaller than it is at present. In fact, as 
Ball points out, "A large proportion of this globe 
on which we dwell may have been derived from 
the little shooting stars which incessantly rain in 
upon its surface." Moreover, this meteor dust 
forms no little part of the "dust motes" we see 
floating in every beam of sunshine. In tropical 
regions, just before sunset in spring, and be- 
fore sunrise in autumn, may be seen a pearly 
radiance arching upward from the sun, in a broad 
ribbon-like belt. This is called the "Zodiacal 
Light." It is formed from tiny particles of 
meteoric matter — "diffused dust" held by the at- 



SHOOTING STARS 171 

traction of the Sun. Opposite it in the heavens 
is the counter-glow or Geyenschein. Sometimes 
in European countries this strange meteoric light 
is seen extending upward like a cone appendage 
to the Sun. 

Usually, if one is observant enough, meteors 
may be seen falling in groups of twos and threes, 
now here, now there ; and at certain periods of the 
year, notably in the months of April, August, 
and November, they occasionally come down in 
showers, as we shall presently see. Always 
more meteors fall in the small hours between 
midnight and six in the morning than at any 
other time. The reason is very clearly ex- 
plained by the fact that when one runs rapidly 
in a rainstorm the chest becomes wetter than the 
back, for the reason that the advance of the body 
meets the drops. Likewise, in its revolution 
about the Sun, the forward part of the Earth is 
struck by more meteors than any other portion. 

The Earth, in this instance, may be likened 
to a great fisherman. Her air blanket is the 
net in which the meteors become entangled and 
thenceforward their career is brief indeed. For 
countless ages these little bodies — chips from 



172 SHOOTING STARS 

great disintegrating comets — have been whirling 
through -space, continued in the immense orbit of 
their parent, and covering probably no less than 
twenty miles per second. We can hardly con- 
ceive of such an enormous speed. 

If a shooting star should decide to encircle the 
Earth, it could travel the 25,000 miles and get 
back to its starting point in a little over twenty 
minutes. No projectile could be fired from one 
of our long-range guns that could keep pace with 
it ; and of course the resistance of our atmosphere 
would be too great for such a projectile. 

It is when it reaches the Earth's net that the 
meteor's "swan song" begins; for this is what its 
little flash really means. It is the death note of 
the meteor. Traveling at such an enormous 
pace, its speed meets with a terrific resistance 
in the air blanket, heat is kindled, and presently 
the little particles which make up the meteor 
turn to gas and flash off in vapor. And then, 
and then only, do we see the meteor; for it is 
too small to be detected even by the largest teles- 
copes, and we get no hint of it until at the very 
moment it begins to be destroyed when its vis- 
ibility begins. And it is gone in an instant! A 



SHOOTIXG STARS 173 

wondrous glowing streak — a shooting star in all 
but reality. 

Obviously, on the infrequent occasions when 
meteors streak the heavens in countless numbers, 
for hours at a time, as in the meteoric showers 
of 1799 and 1833, some reason other than the 
attraction of the Earth must be found. Care- 
ful watching showed the astronomers that in the 
case of every shower the luminous streaks, if 
prolonged backward, met in a certain small area ; 
that is, they had a radiant point, and, owing to 
perspective, seemed to fall in parallel lines. It 
was easy, then, to chart the showers with ref- 
erence to the nearest neighboring constellation 
and to give the name of this figure to the meteors. 
Thus we have Leonids, Perseids, Lyrids, and 
Andromedids from the constellations of Leo, 
Perseus, Lyra, and Andromeda respectively. 
All in all, about 300 radiants are now known, 
fifty of these being quite well established, but the 
four mentioned above form the most brilliant 
showers, and hence are the best known. 

Having satisfactorily located the showers, the 
next thing was to determine their path or orbit 
and, if possible, to learn their origin. Mathe- 



174 SHOOTING STARS 

maticians pointed out that the meteors traveled 
a lengthened orbit, much more like that of a 
comet than a planet. Then came the mirac- 
ulous meteoric shower of November, 1833, when 
from the terrible rain of "fire and brimstone," ig- 
norant peoples everywhere fancied the end of the 
world was at hand. For nine hours the stars fell 
"like flakes of snow, . . . varying in size from 
a moving point or phosphorescent line to globes 
of the Moon's diameter." Astronomers were 
quick to note this phenomenon was exactly thirty- 
four years from the time of a similar shower 
which had appeared from the same constella- 
tion — that of Leo; moreover, it was observed 
that the apparent orbit of these meteors was the 
path traveled by Temple's comet. Likewise it 
was found that the August showers, the Perseids, 
pursued the same track as Swift's comet (known 
as the bright comet of "1862, III"), and sus- 
picions grew that comets and meteors had some 
well-established affinity. The orbit of Swift's 
comet runs way out beyond the planet Neptune, 
making a period of 120 years necessary to com- 
plete its circuit. Obviously no real proof could 
be had from it, but in the case of Temple's comet 



SHOOTING STARS 175 

it was not hard to reckon the date for another 
meteoric display, which Newton fixed as the 
evening of November 13, and the morning of 
November 14, 1866, and which subsequently 
came off exactly as scheduled in a glorious dis- 
play, well-calculated to delight the hearts of the 
astronomers. But it was not until the Bielid 
shower, of November, 1872, which we have al- 
ready recorded, marking the disintegration of 
Biela's comet, that the world was satisfied that 
meteors were no more nor less than the small 
chips and dust particles of comets, which are 
thrown off by reason of the burning-out process 
exercised by the Sun and the attraction of the 
planets. One other puzzling question yet re- 
mained : Why was it that the Earth apparently 
hit some of these meteors every year, but only 
once in a certain number of years seemed to run 
right into the midst of them? This problem, too, 
was solved, as follows: 

"One has only to imagine," says one authority, 
"a swarm of such meteors at first hastening 
busily along their orbit, a great cluster alto- 
gether, then, by the near neighborhood of some 
planet, or by some other disturbing causes, be- 



176 SHOOTING STARS 

ing drawn out, leaving stragglers behind, until 
at last there might be some all round the path, 
but only thinly scattered, while the busy import- 
ant cluster that formed the nucleus was still 
much thicker than any other part. Now, if the 
orbit that the meteors followed cut the orbit or 
path of the Earth at one point, then every time 
the Earth came to what we may call the level 
crossing she must run into some of the stragglers, 
and if the chief part of the swarm took thirty- 
three years to get round (as in the case of the 
Leonids), then once in about thirty-three years 
the Earth must strike right into it. This would 
account for the wonderful display. So long 
drawn-out is the thickest part of the swarm that 
it takes a year to pass the points at the level 
crossing. If the Earth strikes it near the front 
one year, she may come right round in time to 
strike into the rear part of the swarm the next 
year, so that we may get fine displays two years 
running about every thirty-three years." l 

It is probable that there are thousands of 
meteoric currents, comprising the residue of 
burned-out comets, in our solar system, and 

i G. E. Mitton, in "The Book of Stars." 



SHOOTING STARS 177 

large numbers must cross the orbits of other 
planets, perchance held in check by other suns 
than ours. Occasionally a chip, manifestly 
larger than the general run, manages to slip 
down through our atmosphere without burning 
itself entirely out, and lodges in the earth, 
whence it is rescued and termed variously as a 
meteorite, an aerolite, or an uranolith. Many 
thousand pounds of such cometary matter have 
been collected from all parts of the earth, and 
are carefully preserved in museums, notably in 
London, Paris and Vienna abroad, and in the 
United States at the Harvard and Yale Univer- 
sities, Amherst College, the museums of New 
York and Chicago, and the National Museum 
at Washington. 

Generally speaking, meteorites are of two 
classes, meteoritic stones and meteoritic irons, the 
former being the more numerous. Meteoric 
stones are encrusted with a thin substance like 
dense black varnish, caused by the heat generated 
in their terrific downward flight. Iron meteor- 
ites are covered with queer pittings, like deep 
thumb marks, due to impressions made while 
white hot by air resistance. The study of 



178 SHOOTING STARS 

meteorites belongs to the province of the chemist 
and the mineralogist rather than to the astrono- 
mer, but so far their analysis has not brought 
to light any new elements. When seen at night 
meteorites have a gorgeous appearance. They 
are like huge fireballs, followed by luminous 
trains of vapor. In the daytime the light of 
both fireball and train is largely lost against 
the deep sky background, and the vapor appears 
only as a bright cloud. As the solid body hurls 
along, a deep, continuous roar is heard, ending 
in one grand explosion, or perhaps in several 
smaller explosions, and finally the mass may 
plunge deep into the earth, or it may burst into 
a number of tiny fragments to be scattered far 
and wide. 

Since the beginning of Time stories of stones 
and iron missiles hurled from heaven by the 
wrath of the gods have been current, but it was 
not until 1803, when a great aerolite fell in 
France, that scientists began to accept the tales 
in the light of truth. Then astronomers vio- 
lently disagreed. Many of them, even such an 
eminent authority as Sir Robert Ball, held that 
meteorites were the residue hurled from volcanoes 



SHOOTING STARS 179 

when the world was in the making, and kept in 
subjection by the Sun, until the Earth came so 
near them that they could not resist dropping 
down upon her. Others argued that the pro- 
jectiles came from the Moon or the Sun. Still 
others, considering that in only two instances 
meteorites had been known to fall in meteoric 
showers, and then with no real proof of probable 
connection, insisted on connecting them with the 
planetoids. There were unanswerable objec- 
tions, however, to all of these theories, and at 
length it was fully determined that the meteorites 
were in truth large "swarms or shoals of me- 
teoric particles" separated from their parent by 
vaporization in the rapid journey through space. 
Ball estimates that at least 100 grand meteor- 
ites fall to the Earth every year. But there 
are few accounts of eye-witnesses of these 
marvelous spectacles ; nor, on the other hand, do 
we read of damages caused by the downfall of 
huge missiles. The largest meteorite on record 
is probably the immense mass called Ahnighito 
(the tent), weighing thirty-seven and one-half 
tons. It was discovered in northern Greenland, 
by Lieutenant Peary, in 1894. With its two 



180 SHOOTING STARS 

smaller companions, "the Woman," and "the 
Dog," it had long formed the source of iron for 
the Eskimos, who held that the three masses had 
been hurled from the heavens by the evil spirits. 
"The Tent" was brought to New York in 1897, 
and now rests under the entrance arch of the 
Museum of Natural History. Humboldt es- 
timated the diameter of the ordinary large size 
fireballs from 500 to 2,800 feet. Such balls 
frequently rival the moon in brightness, and 
leave behind them a long comet-like train of 
light. One or two instances have been noted 
where the train of a fireball remained in full 
view for half an hour after the meteorite itself 
had vanished, due it is supposed to phosphor- 
escence. 

Amazing as are these great detonating fire- 
balk, darting without warning upon us from 
the depths of space, as though hurled from the 
mighty arms of the angered god of the thunder, 
they yet find their rivals in sheer magic in their 
small kindred, which weigh at best only a few 
ounces. These latter are truly the final marvels 
of the solar system. They show us our Sun in 
a new light. We see him as a condescending 



SHOOTING STARS 181 

ruler, mindful of even the tiniest object in his 
kingdom — the shooting stars. Whether of the 
size of a bullet, a common rifle shot, or even a 
tiny grain of sand, he holds them in an elliptic 
course around him as carefully as he does the 
great king of the planets, Jupiter himself. 
Whole shoals of infinitesimal meteors are inspired 
by his gentle might to pursue their miraculous 
journey in one common purpose, each one push- 
ing on serenely in its path, independent of its 
neighbors, round and round, year in year out, 
content with its lot of allegiance, until, presto! 
it is whisked from the path by the force of 
Mother Earth's alluring charms, and perishes 
in a final picturesque flash of light. "The soul 
of a departed one," the Indians -murmur softly, 
when they see it. 



IX 

COLORED AND DOUBLE STARS 

No doubt if any one asked you the color 
of the stars, you would answer white without 
an instant's hesitation. But, suppose you care- 
fully scan the heavens the first clear night: you 
can not help seeing that some stars show reddish 
or yellowish tints, others shine with a steely 
blue light. Looked at through a telescope these 
stars resolve themselves into brilliant individual 
colors: the red stars are bright red, copper red, 
blood-red, "glowing like a live coal," etc. Like- 
wise the blue, green, and yellow stars shine out 
in various tints and shades of the most vivid 
types. There is a message in this wealth of 
color, which the spectroscope readily aids the 
astronomer to read. It tells him of what 
elements these various suns are composed: thus 
the red stars are largely carbon; the blue are 
hydrogen; the yellow ones show a mixture of 
elements like our Sun; and so on- 

182 



COLORED AND DOUBLE STARS 183 

But the most interesting thing about these 
colored stars is that they are nearly always 
double; that is, they are made up of two stars 
so close together that the naked eye is unable 
to separate them. At first astronomers could 
not believe what the glass told them. They 
thought that these stars seemed to be doubles 
only because they happened to be nearly in the 
same line of sight from the earth. It was sup- 
posed that one star might easily be many millions 
of miles in space behind the other. Several such 
pairs- of stars were already known to exist in 
the heavens; astronomers termed them optical 
doubles. Certain reasons, however, argued 
against classing the colored doubles with these 
stars, and the problem stood unsettled until 1802, 
when Sir William Herschel proved that the 
puzzling doubles were in truth just what they 
seemed. They were saved from coming together 
by mutual attraction and ending in an inglorious 
crash — the chief argument against believing in 
two stars so closely associated- — because both 
were in motion, one revolving around the other. 
They were confined at certain distances by the 
laws of gravitation, just as our Sun and the 



184 COLORED AND DOUBLE STARS 

planets are. To distinguish this class of doubles 
from those which merely seemed to be doubles, 
Herschel suggested calling them binary stars, 
and this name still stands. 

Many of the brightest stars in the sky are 
binaries. Alpha-Centauri, our nearest fixed 
star, you remember, is included among these. 
It is made up of two very bright stars, which 
take eighty-one years to travel round their orbit. 
At their closest point they come as near to- 
gether as Saturn is to the Sun — 886 millions of 
miles ; when farthest their distance is far beyond 
that of Neptune from us. Sirius, the brightest 
star in the sky, and Castor, one of the well- 
known "Twins" in the constellation of Gemini, 
are two other doubles easily observed by the 
smallest telescope. 

Castor is one of the most familiar of the double 
stars, and astronomers long ago discovered that 
one star is revolving slowly about the other — so 
slowly that several hundred years are required 
for a complete circuit. This is not so surprising 
when we remember that Castor is so remote from 
us, that the two stars instead of almost touching 
each other are really hundreds of millions of 



COLORED AND DOUBLE STARS 185 

miles apart. If, for illustration, we could be 
upon one of these gigantic worlds observing our 
own solar system in the heavens — and if one of 
our outermost planets, say Neptune, should be 
enlarged to a size near that of the Sun — then 
Neptune and the Sun would form a double star, 
slowly revolving the one about the other. The 
intermediary planets would be invisible, unless 
some extremely powerful Castorian glass should 
pick up Jupiter, as a tiny satellite hovering near. 
Upwards of 12,000 double stars have been 
counted in the heavens, and the orbits of many 
of them successfully calculated. Strangely 
enough, many of these doubles were discovered 
simply by inference, irregularities in certain stars 
having suggested the influence of another body, 
just as the action of Uranus led astronomers 
to suspect the existence of Neptune long be- 
fore they were actually able to prove his exist- 
ence. In some instances triple, quadruple, and 
even more stars have been discovered banded to- 
gether in this* miraculous fellowship. "These 
multiple systems vary from one another in almost 
every case," says Mitton. "Some are made up 
of a mighty star and a comparatively small one; 



186 COLORED AND DOUBLE STARS 

others are composed of stars equal in light -giv- 
ing power — twin suns. Some progress swiftly 
round their or.bits, some go slowly; indeed, so 
slowly that during the century they have been 
under observation only the very faintest sign 
of movement has been detected; and in other 
systems, which we are bound to suppose double, 
the stars are so slow in their movements that 
no progress seems to have been made at all." 
An especially interesting feature about double 
stars is that the two partners are often of con- 
trasting colors. The most beautiful example 
within range of the ordinary telescope is Beta- 
Cygni in the constellation known as "The Swan." 
The larger star is reddish-yellow and the smaller 
one sapphire-blue. Antares, already mentioned 
as a fiery red star in Scorpio, one of the Zodiac 
constellations, has a small green companion. 
Other double stars show pairs of "yellow and 
rose-red, golden and azure, orange and purple, 
orange and lilac, copper-color and blue, apple- 
green and cherry-red, and so on. In the South- 
ern Hemisphere there is a cluster containing so 
many stars of brilliant color that Sir John Her- 
schel named it "The Jeweled Cluster." "Here 



COLORED AND DOUBLE STARS 187 

are to be seen companion suns in cream-white, 
rose-color, lilac, russet, fawn, buff, and olive hues 
in endless numbers. 

Imagine our sun sharing his kingdom with 
a royal purple companion ! But stay, could our 
planets exist under the pull of two suns in op- 
posite directions? Astonishing as these sug- 
gestions seem, it is certain that conditions even 
more amazing exist in some of these double stellar 
systems. For, besides these glowing suns, they 
contain huge dark bodies which may very well 
be planets. Indeed, says one authority, "In 
some cases the dark body which we cannot see 
may even be larger than the shining one, through 
which alone we can know anything of it. Here 
we have a new idea, a hint that in some of these 
systems there may be a mighty earth with a 
smaller sun going round it, as men imagined 
our sun went around the earth before the real 
truth was found out." In the famous quadruple 
system of Zeta-Cancri three bright stars are 
supposed to revolve round a dark body, which 
appears to be by far the largest of the four. 

So far as we know, many of these stellar 
bodies may be the homes of human beings. If 



188 COLORED AND DOUBLE STARS 

so, what an endless variety of celestial sights 
must delight the eyes of a dweller in this part 
of the Universe! Proctor, in his interesting 
work, The Expanse of Heaven, pictures a world 
where twin suns, one blue and the other orange, 
rise together to produce "double day," or per- 
chance as the orange sun sets the blue one rises, 
and there is no night. "The skies must be ex- 
ceedingly beautiful," he tells us. "Our clouds 
have their silver lining because it is the light of 
the Sun which illumines them. Our summer 
sky presents glowing white clouds to our view, 
and at other times we see the various shades 
between whiteness and an almost black hue. 
. . . But imagine how beautiful the scene must 
be when those parts of the cloud which would 
otherwise appear as simply darker shine with 
a fuller blue light or with a fuller orange light. 
How gorgeous again must be the coloring of 
the clouds which fleck the sky when one or other 
sun is setting." 

From double and multiple stars it is but a 
step to groups and clusters of suns, and here 
again we have a picture of another system of 
worlds. The Pleiades or Seven Sisters is the 



COLORED AND DOUBLE STARS 189 

most famous star group or cluster. It is a no- 
ticeable object in the winter skies, and under the 
telescope resolves into some five or six hundred 
stars, which are in turn multiplied fivefold on the 
resourceful photographic plate. Another inter- 
esting cluster is that of "the Beehive" in the con- 
stellation of Cancer. But perhaps the very fin- 
est star cluster in the whole heavens is that 
known as "Messier 13." This is the famous 
cluster in the constellation of Hercules. It can- 
not be seen as a cluster to the naked eye. It is 
just visible as a faint star. Yet studied through 
powerful lenses it is found to contain at least 
50,000 stars which are estimated as 200 times 
brighter than our Sun. "The total number of 
stars in this cluster, as in others of the globular 
type," says Serviss, "cannot be counted, because 
of their increasing density towards the center, 
but reasonable estimates show that there must be 
hundreds of thousands and possibly a million of 
them, the most of which are giants compared with 
the Sun." Seen through a telescope for the first 
time, the amateur, according to an old Scottish 
astronomer, "cannot refrain from a shout of 
wonder." 



190 COLORED AND DOUBLE STARS 

Imagine what it would be like to live on a 
planet situated in the middle of a star group 
such as the Herculean cluster! Such a world 
would be bathed in perpetual day. One sun af- 
ter another would blaze its fiery way across the 
heavens; and if by chance the larger ones should 
give way to a semblance of night, then their sky 
would be brilliantly pointed by countless stars of 
the first magnitude. But it is doubtful if their 
sky would ever be dim enough to see even these. 
Their astronomers would be in utter ignorance 
of the stars and planets as we know them. 

In thinking of the stars as suns, naturally we 
have pictured them as suns of the same model 
as our own, but we see now how erroneous such 
a supposition would be. Indeed, there are so 
many different groups and double suns in the 
heavens, that it is possible that solitary suns 
such as ours are the exception and not the rule 
in the vast reaches of the stellar universe. More 
and more it is borne in upon us that the world in 
which we live is but one kind amid an infinite 
variety of worlds. We are lost in the contem- 
plation of a Universe without bounds, a Uni- 
verse in which our Earth sinks into "an abso- 
lutely insignificant atom," 



THE, MILKY WAY 

Pure leagues of stars from garish light withdrawn 
Behind celestial lace-work pale as foam, — 

I think between the midnight and the dawn 
Souls pass through you to their mysterious home. 

— William Hamilton Hayne. 

Milton also spoke of the Milky Way as: 
"The way to God's eternal house." Tile Norse- 
man saw it as the path to Valhalla, over which 
traveled the souls of heroes who fell in battle. 
In Hiawatha, we are told how Nokomis taught 
the little Indian lad about the stars that shine 
in the heavens : 

Showed the broad white road in heaven, 
Pathway of the ghosts, the shadows, 
Running straight across the heavens, 
Crowded with the ghosts, the shadows, 
To the Kingdom of Ponemah, 
To the land of the hereafter. 

In Sweden the peasantry speak of the Milky 
Way as the "Winter Street," and Edith M. 

191 



192 THE MILKY WAY 

Thomas has woven this thought into some 
beautiful verses, beginning: 

Silent with star-dust, yonder it lies — 
The Winter Street, so fair and so white; 

Winding along through the boundless skies, 
Down heavenly vale, up heavenly height. 

Ancient peoples of various races have likened 
the Milky Way to a broad river. It was into 
this stream, the river of heaven, that the burning 
chariot of the Sun was plunged on the occasion 
of Phaeton's mad drive. Our English ancestors 
often spoke of the Milky Way as "Jacob's 
Ladder." So we might go on recounting one 
symbol after another that has been suggested 
to different peoples since time began. But 
grander than any of these fanciful thoughts is 
the real truth of this magnificent arch across 
the zenith of our night-time skies. It is a 
mighty circle of light, science tells us, ' 'com- 
posed of worlds heaped on worlds, suns towering 
beyond suns, in a profusion that startles the 
imagination and awes the soul." 

For centuries the galaxy, as this mysterious 
circle is scientifically termed, has been an object 
of close interest among the astronomers. 




THE MILKY WAY AROUND THE STAR CLUSTER, MESSIER II. 



THE MILKY WAY 193 

Aristotle thought that it might be due to atmos- 
pheric vapors. Another early student inclined 
to the absurd notion that the galaxy was the 
shadow cast by the Earth on the heavens. Soon, 
however, scientists began to feel sure that it was 
a broad path of stars too far away to be sep- 
arately seen, and when Galileo turned his newly- 
invented telescope upon it, this supposition was 
found to be the true one. But Galileo's tele- 
scope was far from powerful enough to resolve 
the galaxy. Certain individual stars stood out 
quite clearly, but back of these was the same 
puzzling field of misty light, suggesting a 
breadth and depth of the stellar universe hitherto 
unguessed. Subsequent telescopes and photo- 
graphs have still left many things about the 
galaxy unsolved. As Mr. Gore most fittingly 
observes: "The Copernicus of the sidereal sys- 
tem has not yet arrived, and it may be many 
years or even centuries before this great problem 
is satisfactorily solved." 

We do know, however, that the Milky Way 
is a mighty star stream — that is a system of stars 
which seem to us to be connected, but which 
may yet be separated by millions of miles. All 



194 THE MILKY WAY 

are mighty orbs, suns of the same type as our 
own Great Ruler. Many of them vastly larger 
than he, others smaller. Each of them, we are 
certain, possible centers of planetary systems, 
and the homes of human beings. Small indeed 
would be our own place in the Universe if viewed 
from this celestial highway. In truth, neither 
our Earth nor any of the other planets in our 
solar system could be seen. Our Sun, if vis- 
ible at all, would be nothing but a faint, a very 
faint star. Indeed, its light might be extin- 
guished, and all the human race, as we know it, 
wiped out, without causing any stir in that dis- 
tant part of the Universe. Professor Ball tells 
us that in this event: "All the stars of heaven 
would continue to shine as before. Not a point 
in one of the constellations would be altered, not 
a variation in the brightness, not a change in the 
hue of any star would be noticed. The thou- 
sands of nebulae and clusters would be absolutely 
unaltered ; in fact, the total extinction of the Sun 
would be hardly remarked in the newspapers 
published in the Pleiades or in Orion. There 
might possibly be a little line somewhere in an 
odd corner to the effect that 'Mr. So-and-So, 



THE MILKY WAY 195 

our well-known astronomer, has noticed that a 
tiny star, inconspicuous to the eye, and abso- 
lutely of no importance whatever, has now be- 
come invisible.' " 

The galaxy extends roughly in a great circle 
entirely around the celestial sphere. Usually 
about half of it is to be seen above the horizon 
on clear moonless nights, like a great belt of 
uneven haziness, stretching from zone to zone, 
and as broad across as three full moons. Be- 
tween Centaurus and Cygnus, it divides into two 
branches. Miss Clerke, in her System of the 
Stars, says: "Involuntarily the image presents 
itself of a great river, forced by an encounter 
with a powerful obstacle to throw its* waters into 
a double channel, lower down merged again into 
one. The intervening long strip of islanded 
rock and gravel might stand for the great rift 
between the branches of the sidereal stratum, 
which, although to the eye, owing to the effect of 
contrast, darker than the general sky, is in re- 
ality nowhere quite free from nebulous glimmer- 
ings. It is encroached upon by fringes, effu- 
sions, and filaments, spanned by bridges of light, 
and here and there half filled up by long, narrow, 



196 THE MILKY WAY 

disconnected masses or pools of nebulae, lying 
parallel to the general flow of the stream." 

Photographs and telescopic views of the 
Milky Way show remarkable rifts and chasms 
which until just recently were regarded as 
glimpses of the depths of space beyond. Now 
scientists have concluded that this "darkness be- 
hind the stars" is, in truth, not space at all, but 
that it marks the presence of non-luminous 
bodies. According to Professor Barnard, of 
the Yerkes Observatory, they are simply "cloud 
masses of dark nebulae whose light has failed 
them, or which never had any light." One of 
these apparent rifts in the Milky Way may be 
plainly noted with the naked eye. It has been 
known to navigators for ages as "the coal sack," 
and is about eight degrees long by five degrees 
broad. Only one star may be marked in this 
space unaided, but several show up under the 
telescope. 

The Milky Way has been termed "the ground 
plan of the Universe." It has long been no- 
ticed that there are more stars in the region 
of the heavens near to its broad path than there 
are in the opposite direction. In short, the stars 



THE MILKY WAY 197 

increase up to the galaxy, which seems to be a 
broad highway for stellar clustering. It is 
apparently the equatorial zone of the stellar uni- 
verse. The stars here appear to be closer to- 
gether than in any other part of the heavens, but 
this may be due to circumstances affecting our 
line of vision. Since this celestial path arches 
about us, it is not unlikely that our Sun is himself 
a member of the Milky Way. Sir John Her- 
schel, who made a study of this portion of the 
stellar system from both hemispheres, inclined to 
the belief that "our situation as spectators is 
separated on all sides by a considerable interval 
from the dense body of stars composing the 
Galaxy." Time, perhaps, may satisfactorily 
solve this stupendous problem, but at present 
nothing seems more unlikely. 

A recent investigator likens the general shape 
of the stellar universe to that of the Great Nebula 
in Andromeda. Furthermore, scientists have 
argued that, while space is undoubtedly bound- 
less and infinite, there is a definite number of 
stars or suns, possibly 500,000,000 or more. 
Were the number of stars as infinite as space 
itself the whole heavens would shine with a 



198 THE MILKY WAY 

brightness equal to that of our Sun. But, even 
granting that the stellar system may have 
boundaries in space, it is yet of a vastness 
entirely outside the comprehension of man. 
Supposing the Milky Way to be the middle zone 
of the stellar universe, mathematicians have cal- 
culated that the nearest sun at the outer edge 
of this broad path is at a distance that must be 
expressed way up in the seventh family of 
numericals, thus 000,000,000,000,000,000,000. 
Any attempt to realize the immense distance 
marked by such a speculative guide post sets 
our heads swimming! Much less, then, can we 
essay to measure the further breadth of this 
marvelous stellar space. And yet this is but 
a beginning. If we would comprehend the whole 
Universe, astronomers say that there may be 
other stellar universes out in illimitable space; 
that is, what we know as the star world may 
have neighboring star worlds, and these their 
neighbors away out in the Infinite Beyond. 

"The number of stars and systems really exist- 
ing, but invisible to us, may be practically in- 
finite," says Mr. Gore. "Could we speed our 
flight through space on angel wings beyond the 



THE MILKY WAY 199 

confines of our limited universe to a distance 
so great that the interval which separates us from 
the remotest fixed star might be considered as 
merely a step on our celestial journey, what 
further* creations might not then be revealed to 
our wandering vision? Systems of a higher 
order might then be unfolded to our view, com- 
pared with which the whole of our visible heavens 
might appear like a grain of sand on the ocean 
shore — systems perhaps stretching to Infinity 
before us and reaching at last the glorious 
'mansions' of the Almighty, the Throne of the 
Eternal." 



XI 

THE CONSTELLATIONS 

Mark Twain once observed that the thing 
that puzzled him the most about astronomy was 
how we found out the names of the stars. Per- 
haps you, reader, may have wondered about this 
very point yourself! Evidently imagination 
played a large part in christening the stars, for 
the heavenly groups, or constellations, as we 
call them, bear the names of figures and animals, 
for the most part so wildly fanciful that it is 
impossible to conceive how any one could have 
gone so far out of the way to imagine anything 
so ridiculous. And yet, beneath these figures, 
wild and fanciful as they are, lie many beautiful 
and ennobling ideas, which are of interest not 
only for their real merit, but as sidelights on the 
earnest efforts made by the early peoples to un- 
derstand what was to them the most appealing 
problem — the relation of the Earth to the 

heavens. 

200 



THE CONSTELLATIONS 201 

The word constellation is made up of two 
Latin words: con, which means together, and 
Stella, meaning stars. In plain English, then, 
the word constellation means stars together. 
Almost all nations have arranged the stars into 
constellations, but it is supposed that the Greeks 
mapped out the geography of the heavens which 
is now used, 1,400 years before Christ, drawing 
largely on the records of the gods and heroes 
associated with the voyage of the fabled ship 
Argo. That they also followed the leading of 
the Chaldeans and the early Egyptians is proven 
by the fact that no less than forty-eight of the 
constellations, numbering all of the largest and 
best known groups, had already been recorded 
by Ptolemy, more than 600 years previous. 
Therefore, the actual date of the invention of 
a name for even one of these popular groups 
is not known ; we only know that they have been 
thus called so long that, as the legal lights 
would say, "the memory of man runneth not to 
the contrary." Consequently, though we find it 
difficult to picture the likeness of a bear, a 
bull, a fish, the most agile of hunters, or what 
not, in the scattered groups of stars which make 



202 THE CONSTELLATIONS 

up the eighty or ninety constellations now cata- 
logued in the stellar world, we still cling to the 
old names as a matter of convenience in refer- 
ring to them. 

If the axis of the earth were straight up and 
down in regard to the plane of the Earth's orbit 
round the Sun, then we should always see the 
same set of stars, regardless of time and season, 
but as the axis is tilted slightly, in winter in the 
Northern Hemisphere we see more of the sky 
to the southward than we can in the summer; 
while in the Southern Hemisphere far more 
stars to the north can be seen at this period. 
Always, however, there is one fixed point in 
each hemisphere round which the other stars 
seem to swing. This is the point directly over 
the poles. Happily, too, there is a bright star 
just where the North Pole would seem to touch 
the sky could it be drawn outward. This is 
the Pole Star. For ages it was the mariner's 
only compass: 

"Coasting, they kept the land within their ken, 
And knew no north but when the Pole-star shone." 



THE CONSTELLATIONS 203 

Bryant in his Hymn to the North Star thus 
apostrophizes it: 

The sad and solemn night 
Hath yet her multitude of cheerful fires; 

The glorious host of light 
Walk the dark hemisphere till she retires; 
All through her silent watches, gliding slow, 
Her constellations come, and climb the heavens, and go. 
And thou dost see them rise, 
Star of the Pole! And thou dost see them set. 

Alone in thy cold skies, 
Thou keep'st thy old unmoving station yet, 
iNor join'st the dances of that glittering train, 
Nor dipp'st thy virgin orb in the blue western main. 

Do you know how to mark the position of the 
Pole Star in the sky? First, you must learn 
to recognize the Big Dipper. Perhaps this has 
already been pointed out to you. If not, you 
will have no difficulty in locating the seven bright 
stars which form this conspicuous object. Of 
course, the position of this constellation, like 
that of every other in the heavens, varies with 
the hour of the night and the season of the year, 
but in the Northern Hemisphere it is always to 
be seen somewhere in a clear sky. In April, 
at eleven o'clock at night, it is high overhead, 
and appears upside down. In September, at 



204 THE CONSTELLATIONS 

the same hour, it is low down in the north, seem- 
ing to rest upon the horizon in an upright posi- 
tion. In July, it is to be found in the west, and 
at Christmas time, in the early evening hours — 
the most favorable time for observation — it is in 
the east. The two stars on the side away from 
the handle of the Dipper are called the Pointers. 
A line drawn about three times as far as the 
distance between the two, in the direction they 
indicate, will lead directly to the Pole Star. 

The Big Dipper is the constellation which 
the ancients designated as the Great Bear. In 
England, it is sometimes called Charles's Wain, 
or Wagon; another name for it is The Plow. 
The Pole Star forms the last star in the tail 
of the Little Bear or Little Dipper, this con- 
stellation is very like the Great Bear, but so 
much smaller and fainter that it is considerably 
harder to locate. The Little Bear is turned the 
opposite way from the Great Bear and its tail 
points in the opposite direction. A large 
amount of imagination is necessary to see a bear 
in either of the figures formed by these constel- 
lations. And who ever heard of a bear with 
a tail! A fox or a dog or almost any other 







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*\ CASSIOPEIA Jl 



ANDROMEDA 




THE GREAT NORTHERN CONSTELLATIONS 



THE CONSTELLATIONS 205 

animal would fit the vague outlines better. 
Ancient peoples, however, of nearly all races, 
saw a bear. Homer spoke of it keeping watch 
upon Orion from its Arctic den, and there are 
countless references to it in both classic and 
modern literature. 

One after one the stars have risen and set, 
Sparkling upon the hoar-frost of my chain; 
The Bear that prowled all night about the fold 
Of the North-star hath shrunk into his den, 
Scared by the blithesome footsteps of the Dawn. 

— Lowell — Prometheus, 

Mythology recognized in the constellation of 
the Great Bear the beautiful Callisto, who un- 
fortunately excited the jealousy of Juno, and 
was changed into a bear by the angry goddess. 
While wandering in the forest the bear, it was 
said, met with her own son and sprang to em- 
brace him. The hunter, all unknowing, raised 
his spear to strike, and Jupiter in pity snatched 
both into the sky, where they became the Great 
Bear and the Little Bear. Juno, however, was 
still very wroth, and not to be cheated entirely of 
vengeance she warned Oceanus never to let them 
come near his watery domains. Hence the 



206 THE CONSTELLATIONS 

Bears must ever wander round and round the 
pole, nor venture to dip their huge bodies beneath 
the horizon. This condition, perforce, gives way 
in the equatorial regions, for there constellations 
which are circumpolar in our latitude begin to 
rise and set. Thus the poet accounts for this 
circumstance : 

We saw the Bears, despite of Juno, lave 
Their tardy bodies in the boreal wave. 

Astronomers speak of the Great Bear and 
the Little Bear as Ursa Major and Ursa Minor, 
which while very high-sounding and scholastic 
is no more nor less than the two simple terms 
rendered in Latin. Zeta, the middle star in 
the tail of the Great Bear, is a famous double, 
which resolves under a small telescope into two 
wonderful stars, commonly known as Mizar and 
Alcor. A sharp eye can detect these doubles 
unaided. In European countries, these stars 
are referred to as "the horse and his rider" or 
"Jack on the middle horse, ,, following the idea 
that this constellation is a plow drawn by three 
horses. In German mythology Alcor becomes 
"Hans the Wagoner," who in return for aiding 



THE CONSTELLATIONS 207, 

the weary Savior was offered the kingdom of 
heaven, knowing himself unworthy, however, 
he begged permission instead to drive the celes- 
tial plow horses, and since time out of mind has 
been seen astride the middle horse. Job spoke 
of "the Bear with her train," thus sensibly seeing 
in the three stars a following of cubs, rather 
than a tail on an animal that has always been 
tailless. Our own Indian tribes pictured the 
three stars as a hunter and his dogs following the 
trail of the stellar bear in a wondrous chase which 
lasted from early spring till autumn, when the 
animal was wounded and its blood sprinkled 
the leaves to crimson, russet and brown. 

The Big Dipper and the Pole Star constitute 
the "Great Star Clock of the North," which has 
guided fleet and caravan over wastes of sea 
and sand since Time immemorial. The Pole 
Star is the center of the great clock face, and 
the Pointer stars form the hour hand. Due 
north on the horizon is 12 P. M. Each quarter- 
circle is six hours, and because the Big Dipper 
seems to swing round from left to right the 
pointers run counter clock-wise. With a little 
practice at drawing imaginary clock-faces round 



208 THE CONSTELLATIONS 

the Pole, you will be able to gauge the time with- 
in a half hour, possibly less. 

A line extending about as far beyond the 
pointers as they are from the Pole Star will show, 
on the opposite side of the Great Bear, a 
large capital W, made up of five or six stars, 
shining so brightly that you will wonder how it 
is that you have never noticed this constellation 
before. This is Cassiopeia. If you look 
sharply, you may perhaps see the lady in the 
chair which the ancients fancied they saw 
in this group. She is the Ethiopian queen 
who dared to set her beauty above the sea- 
nymphs, and was sentenced by the gods 
to be bound in her chair and swung into the 
heavens, where she might revolve around the 
Pole, now head upward now downward, in order 
to teach her humility. In looking at Cassiopeia, 
you will note, of course, that this constellation 
seems to be on or near the great belt of the 
Milky Way, with which we are already famil- 
iar. 

The Pole Star, the Dippers, and Cassiopeia 
constitute what is called the Great Northern Con- 
stellation, and serve as convenient celestial land- 



THE CONSTELLATIONS 209 

marks, which are always at hand, for mapping 
out the heavens. You will find it interesting 
to trace out by their help others of the best 
known groups in a personally conducted tour 
of your own. A good star atlas would make 
things a bit easier perhaps, but you really do not 
need it, if you are good at executing imaginary 
lines and angles. Above all, avoid trying to lo- 
cate the constellations by the aid of maps out- 
lined in the grotesque figures fancied by the prim- 
itive people. These only lead to confusion. 
Such figures never existed save in the richest 
imaginations, and one should never attempt to 
picture them in the sky until after the group with 
which they are associated is well-known. They 
are interesting only as side-lights on the begin- 
nings of a subject which is apt at times to be- 
come too solid, and they have absolutely no 
place in any real study of the geography of 
the sky. 

Before going on with the constellations, we 
must prepare ourselves to understand the de- 
signations used by astronomers to indicate the 
magnitude or brightness of the stars. In gen- 
eral, small letters of the Greek alphabet are used 



210 THE CONSTELLATIONS 

to denote the most prominent stars of a group. 
a represents its brightest star, the next, y the 
third, and so on. As a further identification, the 
Greek letter followed by the Latin genitive of 
the constellations shows to what group it belongs : 
thus a Orionis is the brightest star in Orion, 
y Andromedse is the third star in order of 
brightness in Andromeda. If a constellation 
has more than twenty-four stars deserving 
especial mention, then the letters of the Latin 
alphabet are used: if these prove insufficient, 
ordinary Arabic numerals follow. Thus we 
have f Tauri, 61 Cygni, and the like. Further 
than this, about one hundred stars have proper 
names, mostly of Arabic origin. These stars 
usually may be expressed in two ways; for ex- 
ample, « Tauri is none other than Aldebaran, 
the well-known Bull's eye, <* Lyrse is the bright 
star known as Vega; P Ursa Ma j oris is Merak 
in the constellation of the Great Bear (the bot- 
tom one of the Pointer stars) . 

Because of the rotation of the earth on its axis, 
all of the constellations except those of the Great 
Northern seem to cross the sky from east to west, 



THE CONSTELLATIONS 211 

rising and setting four minutes earlier each 
night. This slow and constant ever-changing 
procession thus brings to each season its own 
constellations, so that star-gazing never loses in 
interest. Always the scene is ever new and yet 
ever old, filled with the fascination of what are 
to us new discoveries and with the welcoming 
of old friends: in spring, Gemini (The 
Twins), Leo and Virgo; in sumnuer Her- 
cules, Scorpio and Bootes; in Autumn, Cyg- 
nus, Pisces, and Aquila; in winter, Orion, Per- 
seus, Canis Major (Sirius) and Taurus (the 
Bull). 

One of the most conspicuous figures during 
autumn and winter is that of the Great Square 
of Pegasus — the final home of the famous 
winged horse of ancient Greece, whose marvel- 
ous doings are doubtless familiar to all, since 
they are so charmingly told in Hawthorne's 
Wonder Book. To reach this Square we draw 
an imaginary line from the Pole Star over the 
end of Cassiopeia and as far again, when we 
come to four stars which if enclosed, would sug- 
gest to our modern minds a big saucepan, instead 



212 THE CONSTELLATIONS 

of the famous horse, and on looking about we 
find that this symbol is quite complete, for there 
is a bent handle attached to the pan! However, 
this is the Great Square of Pegasus, winged 
horse or not, and it is located in one of the most 
interesting tracts of Star-land. Half-way be- 
tween one corner of the square or "pan" and Cas- 
siopeia is the Great Nebula in Andromeda. 
The star in the handle is an exquisite orange- 
colored double with a sea-green companion. 
Near the end of the handle is Perseus. Some 
of you may perhaps recall the tale of this hero's 
marvelous quest in sfeach of the Medusa's head. 
When he and Andromeda, the daughter of 
Cassiopeia, whom he rescued from the cruel fate 
to which her mother's sins had bound her, were 
snatched up into the sky, there to regain peace, 
Perseus triumphantly bore with him the Medusa's 
head. Algol, the wonderful variable star, is the 
"baleful, blinking demon-eye" of this terrible 
head, "which about every third day drops from 
the second magnitude to the fourth and recovers 
in a few hours." The reason for this astonishing 
diminution of brightness is attributed to the 
fact that Algol has a dark companion, about the 



THE CONSTELLATIONS 213 

size of our Sun, which in the circuit of its orbit 
manages to come in between the star and the 
observer and partially cuts off the light; Algol 
himself being a star about one million miles in 
diameter. 

A sharp curve to the left from Perseus draws 
the eye to Capella, "the goat" in the wide-spread- 
ing constellation of Auriga, the Charioteer. 
Capella is a bright star of the first magnitude, 
which we already know as a sun four thousand 
times larger than our own brilliant orb. Not 
far from Capella is an odd arrangement of three 
stars in a triangle, the "Hoedi" or three kids, 
so the fertile minds of the ancients termed them. 
Capella was supposed to nurture these frisky 
animals, who were held in such evil repute that 
a poet in the third century B. C. counseled the 
mariners, — 

Tempt not the winds, forewarned of dangers nigh, 
When the Kids glitter in the western sky. 

In late autumn and winter Capella rises high 
up in the sky, and then there may be seen below 
her and somewhat to the westward the famous 
Pleiades, or Seven Sisters, only no one has ever 



214 THE CONSTELLATIONS 

seen more than six stars with the naked eye. 
In the old days people attached particular good 
luck to the number seven; so it is quite possible 
that those who named this constellation invented 
the tale of the lost Pleiad, which has cropped 
up in literature since time out of mind. An old 
writer tells us that the Berbers and Dyaks lo- 
cated the center of the Universe and the abode of 
the Deity in the Pleiades. "With November, 
the Pleiad month" — when this constellation 
reaches its highest pinnacle in the southeastern 
heavens — "many primitive people began their 
year; and on the day of the midnight culmina- 
tion of the Pleiades, November 17, no petition 
was presented in vain to the ancient kings of 
Persia. The same event gave the signal at 
Busiris for the commencement of the feast of 
Isis. . . . Savage Australian tribes to this day 
dance in honor of the 'Seven Stars,' because 
'they are very good to black fellows.' ' Alcy- 
one, the brightest star of the group, reaches its 
best period about the time of the winter solstice, 
when all the world is sunk for a few days in 
restful calm. Sometimes this is a "golden 
cluck-hen" with her brood of chickens about her; 



THE CONSTELLATIONS 215 

again it is a girl feeding her flock. Classical 
poets have fancied the Pleiades as a flock of 
pigeons fleeing from Orion, the hunter. Bayard 
Taylor styles them as "golden bees upon the 
mane of the bull." While Tennyson likens 
them to ^a glittering "swarm of fire-flies tangled 
in a silver braid." To the Greeks, they were 
sailing stars, their rising in May betokening the 
time for the opening of navigation, hence the 
name Pleiades, derived from their verb, meaning 
"to sail." Owing to what astronomers term the 
precession of the equinoxes — which is literally a 
gliding backward or westward of the equinoxes, 
about fifty and one-fourth degrees annually, due 
to the slow movement of the equator round the 
ecliptic, — the Pleiades no longer rise in May. 
They are not seen until about September 1, 
when they appear low down to the east. By 
the first of March this interesting group has 
apparently progressed around to the western sky 
and may be seen setting about 11 p. m. 

As the Pleiades begin to mount into the heav- 
ens, a glorious reddish star of the first magnitude 
rises beneath them, and a little to the southeast. 
This is Aldebaran, which is already well-known 



216 THE CONSTELLATIONS 

to us. It is the bright star of the Hyades group, 
which mythology terms half-sisters of the 
Pleiades, and with them forms a part of the 
constellation of Taurus the Bull. The Hyades 
are described by the poet as "whitening all the 
Bull's broad forehead." The name comes from 
the Greek word rain, and when these stars are 
close to the horizon "a spell of weather" may be 
expected. "In the showery springtime," says 
Porter, "they set just after the sun, and in the 
stormy period of late fall just before sunrise. . ." 
The classic writers again and again refer to them 
as the rain stars; Spenser called them "moist 
daughters," and in Tennyson's Ulysses we read: 

Through scudding drifts the rainy Hyades 
Vex'd the dim sea. 

The glory of our winter skies is the constella- 
tion of Orion, pronounced as though written 
O'Ryan. It is often called the "Wild Irishman 
of the Skies," and was always pictured by the 
ancients as a marvelous giant swordsman. This 
constellation may be located a little to the east 
and southward from Aldebaran. A line drawn 
from the Pole Star down through Capella and 



THE CONSTELLATIONS 217 

"produced as much farther again" strikes the 
western corner of a long irregular four-sided 
space in which may be seen the belt of the hunter, 
set as three slanting stars. Below these, as 
though dropped from them, are three more stars 
in the position of a sword. Two brilliant suns 
of the first magnitude mark this splendid figure 
unerringly for all eyes : Betelgeuse, with whose 
prowess we are already familiar, is located from 
its name, meaning "armpit" ; Rigel, whom some 
astronomers term Algebar, is on the opposite 
lower corner. Bellatrix, "The Female Warrior 
or Amazon Star," is a star of the second mag- 
nitude, as are also the three stars in the belt and 
the star at the lower corner toward which they 
point. According to Porter, "The three stars 
in the belt constitute the golden yardarm of sea- 
men, and the yardstick or ell of tradesmen, be- 
sides being popularly known as the Magi or 
three wise men from the Orient, and the three 
Marys." The same authority also tells us that 
by reason of the fact that Orion was supposedly 
swung up to heaven to teach men not to be 
too confident of their own strength, a committee 
of the University of Leipsic, in 1807, resolved 



218 THE CONSTELLATIONS 

that the stars belonging to the belt and sword 
of Orion should in the future be called Napoleon. 
Their resolution, however, failed to meet the ap- 
proval of astronomers at large, and map-makers 
have given the suggestion small heed. As 
Orion lies on the celestial equator, he is equally 
familiar to the peoples of the North and the 
South, and he has been a favorite allusion with 
poets and writers of all time, being several times 
mentioned in the Bible. Dominating the skies 
as he does at a season when squally weather is 
rife, it is not to be wondered that he is blamed 
for much of the unpleasantness. Indeed an 
ancient writer goes so far as to state that the 
loss of the Roman fleet during the first Punic 
war was caused by the "obstinacy of the consuls, 
who, despite the pilots, would sail between the 
risings of Orion and Sirius, always a squally 
time. ,, 

Sirius, you remember, is the Dog Star, other- 
wise known as Canis Major, and the brightest 
star in all the heavens, being many times brighter 
than any other star of the first magnitude, and 
therefore in a class quite by himself. If the line 



THE CONSTELLATIONS 219 

of Orion's belt be drawn on downward in the 
direction indicated by these stars, Sirius will 
presently be met. But it takes a lively imagina- 
tion to picture the figure of a dog in the five or 
six naked eye stars which make up this constella- 
tion! The name Sirius comes from the Greek, 
and signifies "scorching" or "sparkling." The 
ancients believed that the fierce rays from this 
star, when at its height, mingled with those of 
the Sun in the torrid days of summer, 
hence the term "dog days." Thus it trans- 
pired that, though marvelously lovely, Sirius 
soon attained a very unenviable reputation 
throughout the northern hemisphere, where it 
was believed his burning breath tainted the air 
with all manner of fevers, plagues, and death. 
In the Nile valley, however, Sirius proved him- 
self quite as double in character, as he is in form ; 
for here, before precession had carried him out 
of range, he rose with the Sun at the time of the 
summer solstice, and hence foretold the joyful 
coming of the rise of the waters. He was, there- 
fore, hailed as the Nile star, the beloved "Star of 
Kneph," and many temples were dedicated to 



220 THE CONSTELLATIONS 

his worship. Unlike most doubles, Sirius shines 
with an intense white light. As he is always 
seen comparatively close to the horizon, his rays 
of light, which are more than eight years reach- 
ing us, are so broken up by their passage through 
the atmosphere, that he seems always to twinkle 
at a marvelous rate. This excessive scintilla- 
tion gives the impression of a many-colored,, 
changing light, which Tennyson thus describes in 
The Princess: 

The fiery Sirius alters hue, 
And bickers into red and emerald. 

A line drawn slanting northeast from Sirius 
leads one to the constellation known as the Little 
Dog, or Canis Minor. This animal is a hound 
belonging to the famous "Heavenly Twins," at 
whose heels he follows. You will note these re- 
nowned hunters, glowing as two bright stars, 
a little to the westward, almost in line with 
Capella. Castor and Pollux they are called, 
and with the stars which make up their very 
sketchy outline form the constellation of Gemini, 
pronounced Jiminy. Henceforth, when you 
hear any one exclaim "By Jiminy!" bear in mind 






THE CONSTELLATIONS 221 

that it is by this constellation they are swearing! 
Castor and Pollux were the sons of Leda, and 
hence are known in literature as the Ledasan 
lights. In The Wanderer, Owen Meredith 
speaks of them thus : 

The lone Ledsean lights from yon enchanted air 
Look down upon my spirit, like a spirit's eyes that 
love me. 

The twins were famous warriors, Castor being 
especially known for his miraculous battle on 
horseback, while Pollux was a pugilist to be 
feared. They were brothers of Helen of Troy, 
and on the return of the much recounted Argo- 
nautic expedition, when a storm threatened to 
destroy the vessel, Apollo, to whom an appeal 
was made, allayed the tempest, and set a star 
on the head of each Twin in token thereof. 
Henceforward The Twins became revered by 
seamen, and their effigies were frequently placed 
on boats as a talisman. The electrical flames, 
known as Saint Elmo's lights, which are fre- 
quently seen playing about the mastheads of the 
vessels in heavy weather, were formerly sup- 
posed to be due to the influence of these mystic 



222 THE CONSTELLATIONS 

Twins. Thus in Longfellow's Golden Legend 
the padrone assures the prince: 

Last night I saw Saint Elmo's stars, 

With their glittering lanterns all at play 

On the tops of the masts and the tips of the stars, 

And I knew we should have foul weather to-day. 

Castor does not appear as brilliant in the heav- 
ens as his brother, but he is in thruth more inter- 
esting. Mention has already been made of him 
as a famous double star, blue in color, and so 
gorgeous and stately, that centuries speed on 
while he revolves about his companion in regal 
majesty. 

Returning again to the Great Bear, we draw 
a line through the last stars of his tail, con- 
tinuing on until we come to Bootes, the Herds- 
man, whom modern peoples would, no doubt, 
style the "Ox-Driver," as he follows the plow 
oxen round and round the pole. The two bright 
stars in front of Bootes are the hounds which 
aided him in the chase. Between these two is 
a fine double star named Cor Caroli, which was 
discovered on the eve of the return of Charles II 
to London, and therefore christened in his honor. 
It has been recorded in history that this well- 



THE CONSTELLATIONS 223 

known merry monarch "never said a foolish 
thing, and never did a wise one." But we must 
not forget that it was he who issued the decree 
for founding the royal observatory at Greenwich, 
thereby giving to the science of astronomy an 
impetus of incalculable value. In the early 
times, Arcturus, already mentioned as a won- 
drous star of the first magnitude, was repre- 
sented as a spear in the hand of a hunter who 
was supposed to be pursuing the Great Bear. 
The Arabs termed it the "Lancebearer." Not 
far from Arcturus is a cluster of stars shaped 
like a horseshoe. This is the Northern Crown, 
or tiara of stars which the ancients connected 
with Ariadne, the daughter of King Minos, of 
Crete, who became the bride of Theseus while he 
was at the height of his Athenian triumphs. 
Later she was deserted by her faithless husband, 
and Venus, in pity, promised to send her an im- 
mortal lover. Accordingly Bacchus, the god 
of wine, wooed and won her, and gave her a 
most glorious crown of jewels as a wedding gift. 
On her death, this crown was transferred to the 
sky, and the gems became a wreath of sparkling 
stars. But the centuries seem to have dimmed 



224 THE CONSTELLATIONS 

their brightness. Today there is only one fairly 
bright star in the collection. However, the 
Northern Crown is interesting to look at, and it 
serves furthermore as a guide-post in locating 
the famous cluster of Hercules, which lies near 
at hand. 

The wonderfully bright star which shines 
nearly overhead in summer is Vega, the harp- 
star, known also as the "arc-light of the sky," 
by reason of its brilliant sapphire hue. By look- 
ing closely you may be able to trace the outline 
of a harp among the small stars near. This 
represents the constellation of Lyra, supposed 
by the ancients to have been connected with the 
harp of Arion, a famous Sicilian musician who 
was once set upon by pirates, who sought to 
wrest from him a valuable prize which he had 
won by his skill. As they were about to throw 
him overboard, Arion requested permission to 
play for the last time on his harp. Nothing 
loath, the robbers settled themselves for a rare 
musical treat, and were not surprised when 
presently the dolphins began to gather about the 
boat in a charmed circle. Amused by the ev- 
ident pleasure of the motionless herd, their eye's 



THE CONSTELLATIONS 225 

failed to take note of their prisoner, and ere they 
were aware he was mounted on the back of the 
largest dolphin and speeding off for the land 
near at hand. To-day this clever dolphin 
reposes among the stars, a little to the east of 
the harp. The ring ne*bula of Lyra is a favorite 
object for the ordinary telescope. Here, too, a 
little northeast of Vega, is a famous quadruple 
star, called the Double-double, whose duplicity 
may be noted by a keen eye. It takes a tele- 
scope, however, to note the two pairs. "Each 
pair," we are told, "seems to be revolving in one 
or two thousand years, and their common drift 
through space renders it probable that the two 
couples form one greater system, whose period 
of revolution must stretch far on towards a 
million years." 

Southeast from Lyra are three bright stars in 
a row which are easily noticeable any starlit 
night from early summer to late autumn. They 
mark the constellation of Aquila, the Eagle. 
But clever indeed must be the imagination that 
traces the outline of an eagle in the surrounding 
stars! The ancients saw in it the ominous bird 
of Jove which bore his missiles of thunder. In 



226 THE CONSTELLATIONS 

its talons it carries the youth Ganymede, whom 
the Great Jove had caused to be seized and borne 
aloft to serve him as a cup-bearer. 

... flushed Ganymede, his rosy thigh 

Half huried in the eagle's down 
Sole as a flying star shot through the sky 
Above the pillared town*. 

— Tennyson. 

The Little Bear and Lyra form the guide- 
posts for another constellation that is associated 
with a well-known tale. We remember that, 
when Phaeton swept from his ill-starred voyage 
as charioteer of the Sun, his friend Cygnus could 
not give him up, and dived so often in the stream 
in search of his body that the gods grew angry 
and changed him into a swan. Later the pen- 
sive bird, which still sailed hither and yon, 
thrusting its head into the water, was caught up 
into the sky, where it forms the figure known as 
Cygnus, the Swan. We will do marvelously 
well, however, if we succeed in tracing an outline 
which in any way resembles this water fowl! 
But the principal stars of this constellation 
form the Northern Cross, and this you may read- 
ily recognize. It is well known to all star- 



THE CONSTELLATIONS 227 

gazers. Lowell gives a beautiful picture of the 
Cross presiding over the opening of the New 
Year: 

Orion kneeling in his starry niche, 
The Lyre whose strings give music audible 
To holy ears, and countless splendors more, 
Crowned by the blazing Cross high-hung o'er all. 

Albireo, in the Swan's head, is a lovely double 
star, formed by two companions of golden and 
azure, so well separated that they make exquis- 
ite objects in the small telescope. 61 Cygni, 
in the left wing, has been mentioned variously 
in these pages. 

The Southern Cross, though in no wise con- 
nected with the constellation of the Swan and 
invisible within the boundaries of the United 
States may be mentioned just here. It forms 
"the night-clock" of those who live within and be- 
yond the tropics. A writer of the southlands re- 
marks : "How often have we heard our guides ex- 
claim in the savannahs of Venezuela and in the 
desert extending from Lima to Truxillo, 'Mid- 
night is past, the cross begins to bend !' ' Whit- 
tier in his Cry of a Lost Soul, cites the Southern 
Cross as a symbol of God's mercy. He pictures 



228 THE CONSTELLATIONS 

a traveling party in the gloomy forests of the 
Amazon, when suddenly through the night lists, 

A cry, as of the pained heart of the wood, 
The long, despairing moan of solitude. 

The guides cross themselves and explain in low 
frightened voices that it is the plaint of a lost 
soul, some unbeliever burning in hell. But there 
is one, who unconvinced, 

Lifts to the starry calm of heaven his eyes, 
And lo! rebuking all earth's ominous cries, 
The Cross of pardon lights the tropic skies. 

THE ZODIAC 

Familiarity with the constellations already 
mentioned will give the amateur a wide range of 
acquaintances in the sky, and will perhaps be 
sufficient for those who do not wish to delve more 
deeply into astronomy. For the others, however, 
there remains yet an interesting trail. It is the 
path marked by the zodiac among the stars. 
The zodiac, you remember, is an imaginary zone 
or girdle, stretching around the celestial sphere, 
in a belt extending eight degrees on either side of 
the ecliptic. Neither the Moon nor any one of 



THE CONSTELLATIONS 229 

the planets can ever travel outside this belt. It 
forms what has been termed "the zoological gar- 
den of the sky," since it is divided into twelve an- 
imal groups, and the term zodiac itself signifies 
the Greek for "a circle of animals." How an- 
cient this division is cannot be told, but it is cer- 
tain that it has at least come down from pre- 
Babylonian peoples. To this zodiacal division is 
traceable, no doubt, the twelve months which 
make up the solar year, each sign measuring the 
progress of the Sun during one complete revo- 
lution of the Moon. Originally the division of 
the zodiac into constellations served as the best 
possible means of noting the positions of the 
heavenly bodies. But since the "animals" named 
are more or less imaginary and rambling, extend- 
ing as each one does over thirty degrees of space, 
accurate astronomy of to-day discards this 
scheme, and positions are taken with reference to 
the ecliptic and their celestial longitude. We 
still speak, however, of the Sun and the planets 
as being in certain constellations, and they are so 
indicated in our calendars and almanacs. Let 
us, then, try to understand what is meant. 



230 THE CONSTELLATIONS 

Imagine the Earth moving round its orbit with 
the Sun in the middle. Now around this draw 
another wide ellipse to represent the zodiac and 
divide it into twelve equal parts, which you un- 
derstand remain always fixed. As the Earth 
moves, a person located at any one point will 
apparently see the Sun continually against a 
different background — that is to say he seems to 
change his position among the stars and to move 
in and across the constellations by reason of our 
revolution. The same rule holds true of the 
Moon and the planets. Thus we say that a 
heavenly body is in a certain constellation when 
it seems for the time being to be a part of it. As 
the planets are always to be found in some one 
of the zodiac constellations, and as the almanacs 
tell us which one this is, we have only to learn 
the stars of the zodiac to locate any planet we 
wish to plot. A sure aid in locating the zodiacal 
constellations is to know at what time they will 
be on our meridian ? that is the line over our head 
due north and south, at nine o'clock at night, 
during a given month. Here is a table by 
months. 



THE CONSTELLATIONS 231 



Astronomical Name 


Common Name 


Time 


Aries 


The Ram 


December 


Taurus 


The Bull 


January- 


Gemini 


The Twins 


February 


Cancer 


The Crab 


March 


Leo 


The Lion 


April 


Virgo 


The Virgin 


May 


Libra 


The Balance 


June 


Scorpio 


The Scorpion 


July 


Sagittarius 


The Archer 


August 


Capricornus 


The Goat 


September 


Aquarius 


The Water-Bearer 


October 


Pisces 


The Fishes 


November 



To find any zodiacal constellation during any 
other month than that here given, subtract two 
hours for each following month. Suppose we 
want to find Aquarius, the water-bearer, in No- 
vember instead of October. We must look for 
it on our meridian at 7 p. M. a and in December, 
at 5 p. m. 

Owing to the precession or backward move- 
ment of the equinoxes, a confusion has re- 
sulted in the constellations of the zodiac and the 
signs of the zodiac. Time was when they were 
one and the same; now the two terms stand for 
something different. The signs of the zodiac 
are symbols for the spaces or parts of the great 
circle which it forms. Two or three thousand 
years ago, when they were christened, the con- 



232 THE CONSTELLATIONS 

stellations stood in the signs of their name; 
since then, these signs have shifted one space to 
the right, while the constellations have, of course, 
stood still. The result is a tangle which, how- 
ever, can be unraveled after a few efforts. 
When the almanac says that a planet is in that 
part of the zodiac whose sign is Aries, this 
does not mean that it is in the constellation of 
Aries. For the constellation of Aries has ap- 
parently moved westward and is now in that part 
of the zodiac indicated by the symbol Tau- 
rus; the constellation of Pisces occupies the 
place indicated by the sign of Aries. We shall 
have no difficulty with this if we remember al- 
ways to shift the constellation one place to the 
right of the sign which bears its name. 

We must not expect to locate the stars of the 
zodiac by the constellations as outlined in the dia- 
grams of the Circle of the Zodiac. Remember 
that for the purposes of illustration these had to 
be made compact; in reality the stars of these 
figures are scattered widely over thirty degrees 
of space, as has been mentioned, and some do not 
even stop there, but range on to some particular 
constellation which stands as a guide-post. We 



THE CONSTELLATIONS 233 

will need a good star map to make any real 
headway in locating the stars of the zodiac. In 
the almanacs our year begins with January. 
The sun is then in the sign Aquarius, hence this 
month is usually indicated by the picture of 
Aquarius pouring water from a pitcher. In 
studying the zodiac, we begin with Aries, which 
the sun formerly entered in March, and read 
from right to left or counter-clockwise, in the 
position which the Earth travels, thus following 
the apparent eastward path of the sun through 
the constellations. The following rhyme puts 
the order of the stars of the zodiac firmly in 
mind : 

The Ram, the Bull, the Heavenly Twins, 
And next the Crab, the Lion shines, 
The Virgin and the Scales; 
The Scorpion, Archer, and He-goat, 
The Man that holds the watering-pot, 
The Fish with glittering tails. 

With some of these constellations we are al- 
ready familiar. It gives us a little heart for 
the task, — a beginning in the great elongated 
wheel or circle which outlines the ecliptic. 
Quickly we search out the Bull and the Heav- 



234 THE CONSTELLATIONS 

enly Twins. But the Ram heads the list: how 
shall we find him? Easily enough, as it hap- 
pens. We have only to draw a line from the 
Pole Star to Alpha in the lower left-hand corner 
of the Great Square of Pegasus; then down- 
ward until we come to two bright stars quite 
close together, and a third one not quite so bright. 
These are the chief stars in the constellation of 
Aries, the Ram with the wondrous golden fleece 
of Argonautic fame. 

Cancer, the Crab, is the most difficult to lo- 
cate of all the zodiacal constellations. He stands 
at the sign which marks the northern tropic, 
where the Sun stops ascending. According to 
old Chaldean philosophers it was just here that 
"the gate of men" was located, by which human 
souls descended to fill the bodies allotted to them. 
Capricorn, in the southern tropic, where the Sun 
again turned, was the gate where the souls were 
received back to heaven. In the constellation 
of Cancer is the famous beehive cluster, already 
mentioned. Mythology styled this the Manger, 
the two stars lying one on either side being 
named the ass's colts. The Manger has not in- 
frequently been mistaken for a comet by inex- 



THE CONSTELLATIONS 235 

perienced eyes. An old writer makes it the 
basis for a clever weather prognostication: 

A murky manger with both stars 

Shining unaltered, is a sign of rain. 

If while the northern ass is dimmed 

By vaporous shroud, he of the south gleam radiant, 

Expect a south wind: the vaporous shroud and radiance 

Exchanging stars, harbinger Boreas. 

Two lines extending down from either side 
of the Dipper, will reach the two chief parts 
of Leo, the Lion, the head and shoulders, or 
what seems to us a sickle, composed of six stars, 
with Regulus, a very bright sun, meaning "little 
king," in the end of the handle. Needless to 
say, it takes a good deal of imagination to pic- 
ture the king of beasts in such a scraggly out- 
line! Much less can we fancy it as the leader 
of the four royal guardians of heaven, or ac- 
count for its wide-spread prestige of greatness 
and power, which brought glory and riches to 
all luck enough to be born under its magic in- 
fluence. 

By drawing a line from the Pole star through 
Mizar in the handle of the Big Dipper, on down 
past Bootes, until a big white star is reached, 



236 THE CONSTELLATIONS 

we arrive at Spica, the Virgin, the chief star in 
the constellation of Virgo. This group is of in- 
terest chiefly because while the Sun is at this 
point it passes the autumnal equinox. The 
Virgin and the harvest were always inseparably 
linked in the minds of the ancients, and she is 
invariably represented with a sheaf of wheat in 
one hand and a sickle in the other. Instead of 
the goddess of the fields, modern minds see in 
this group a huge star diamond outlined against 
the blue. It is the largest of the zodiacal con- 
stellations, and stands in the field where there 
are comparatively few stars, being quite remote 
from the Milky Way, in a region where the 
nebula? congregate in rich numbers. 

The scales mark the constellation of Libra, 
the Balance. "In all the round of the zodiac," 
says Porter, "this constellation alone represents 
an inanimate object; and its antiquity, though 
somewhat in dispute, does not seem to be very 
great. Certain it is that the Greeks associated 
its stars with the claws of the Scorpion which 
follows to the east. Scorpio, indeed, seems to 
have been considered a double sign, thus com- 
pleting the twelve," 



THE CONSTELLATIONS 237 

I bear the scales, when hang in equipose 
The night and day. 

Thus wrote Longfellow, in his Poet's Calen- 
dar 'j striking the key note for the birth of this 
constellation, which took place at a period when 
the autumual equinox was in the sign of the 
zodiac, thereby suggesting the figure of the bal- 
ance, corresponding to equal nights and days. 
The constellation is a rather dim and poor affair, 
and we should probably miss it altogether save 
that Alpha, its brightest star, is the connecting 
link between Spica in Virgo and Antares in 
Scorpion. The latter constellation is one of the 
few which really looks its part. Its heart is the 
big bright red star Antares, the king of suns, 
and an interesting double in the bargain, whose 
green companion lies so near as to be frequently 
enshrouded in his flaming rays. The name 
Antares comes from the Greek and signifies 
"the rival of Mars," this star being in truth the 
only one in the heavens which could by any 
chance be mistaken for the red planet. When 
Mars chances to be in Scorpion it takes nice 
discrimination to tell them apart. 

Sagittarius, the archer, is christened in honor 



238 THE CONSTELLATIONS 

of the ancient centaur or man-horse. He is the 
patron of the hunt and the chase, and is always 
pictured shooting an arrow from a bow at the 
fiery heart of the Scorpion. We find Sagit- 
tarius easy to locate, as it lies where the path of 
the zodiac crosses the Milky Way. One of its 
most outstanding features is the little milk dip- 
per, formed of seven stars, and lying turned up- 
side down. There are also several interesting 
star clusters and nebulae in this constellation. 
The winter solstice is marked half-way between 
the constellation of Scorpion and Sagittarius, at 
a point between the two streams of the Milky 
Way. In ancient times Capricornus, the sea- 
goat, marked this solstice ; then the constellation 
occupied the lowest or most southern part of the 
zodiac. Note Milton's lines: 

Some say the Sun 

Was bid turn reins from the equinoctial road 

Up to the tropic Crab; thence down amain, 
By Leo and the Virgin and the Scales, 
As deep as Capicorn, to bring in change 
Of seasons to each clime. 

Capricornus is now a constellation of autumn. 
Of course, he looks no more like a goat-fish than 



THE CONSTELLATIONS 239 

Sagittarius looks like a man-horse. But so the 
early peoples pictured him, and the astrologers 
reckoned that person fortunate indeed who was 
born under this sign of the zodiac. Capricornus 
is easily found by drawing a line through Vega 
in Lyra and on to Altair in Aquila and thence 
to the path of the zodiac. The two brightest 
stars of Capricornus are in his goat-like head. 
One of these stars is a famous naked-eye double. 
In the days of the ancients, however, it took an 
especially good eye to detect this, and hence it 
belonged to the "test" stars. The doubles, we 
are told, "are separating at the rate of one min- 
ute of an arc in about thirteen hundred years, 
their present distance being six minutes." This 
corresponds to a distance of about forty-eight 
quadrillion miles. Another bright star of the 
sea-goat is to be found in his fish-like tail. Of 
course, it was inevitable that Capricornus 
should become associated in mythology with the 
god Pan, who was also part goat. Indeed, 
Capricornus is himself the god Pan in his goat- 
like disguise; for, being attacked by a great fire- 
breathing typhon, Pan jumped into the sea to 
save himself. Here he shortly threw out a finny 



240 THE CONSTELLATIONS 

tail and became amphibious. Pictures of this 
constellation, therefore, always show a curious 
animal with the head and horns of a goat and a 
body which slopes off into the hinder parts of 
a great fish. 

Aquarius is the man with the watering-pot. 
His is a constellation of autumn, but the stars 
which form it are faint and hard to find. It 
is located in that part of the sky which the 
Chaldeans designated as "the sea." The dol- 
phin, Cetus the whale, three fishes, and a goodly 
company of other aquatic creatures are among 
his near neighbors. The Romans gave to him 
his name of the Waterman, because in the long 
ago when the sun entered the sign of Aquarius, 
in January, there were usually heavy rains 
throughout Italy. 

The "Fish with glittering tails" is the constel- 
lation of Pisces. This last member of the 
zodiacal group is really twins, being fashioned 
of two fishes, widely separated, but having their 
tales connected by a ribbon. It is not an inter- 
esting constellation to look at with the naked 
eye, for its stars stream out in two faint lines, 
spreading away beyond their own division of the 



THE CONSTELLATIONS 241 

zodiac in a confusing fashion that is hard to fol- 
low. But Pisces is none the less a very impor- 
tant constellation, because it is at one of the 
points where the line of the equator crosses the 
ecliptic. This occurs about the twenty-first of 
March, or at the time of the spring equinox, 
which, because the days and the nights are then 
of equal length all over the earth, is called the 
vernal equinox. Pisces is very nearly starless. 
Some ancient peoples referred to this constella- 
tion as "Venus and Cupid," the mythological 
tale being that Venus, having been frightened 
by the giant Typhon, threw herself and the child 
Cupid into the Euphrates to escape from him. 
The gods, in pity, changed them to fishes, and 
later fixed them in the sky. Formalhaut, the 
bright star in the constellation known as the 
"Southern Fish," is located south of Aquarius 
and should not be confused with the fishes of 
Pisces. 

"the infinite meadows of heaven " 

Outside the familiar constellations and the 
more complicated path of the zodiac, there yet re- 
mains a limitless host for those who would go 



242 THE CONSTELLATIONS 

farther. One thing deters : As we consider the 
universe of the stars, we find ourselves utterly 
without adequate scales for measurement. 
Even the vast scale of millions of miles used in 
determining the points of the solar system is 
useless here. We must think in billions and 
hundreds of billions of miles. We are lost in a 
marvel of Infinity and Eternity — a Universe 
totally without bounds, having absolutely no be- 
ginning or end in time. And thus it must ever 
be: 

I open my scuttle at night and see the far-sprinkled 
systems, 

And all I see, multiplied as high as I can cipher, edge but 
the rim of the farther systems: 

Wider and wider they spread, expanding, always expand- 
ing. 

Outward, outward, and forever outward: 

My sun has his sun, and around him obediently wheels; 

He joins with his partners a group of superior circuit, 

And greater sets follow, making specks of the greatest in- 
side them. 

"There is no stoppage, and never can be stoppage. 

If I, you, the worlds, all beneath or upon their surfaces, 

and all the palpable life, were this moment reduced 

back to a pallid float, it would not avail in the long 

run. 
We should surely bring up again where we now stand, 
And as surely go as much farther — and then farther and 

farther. 



THE CONSTELLATIONS 243 

A few quadrillions of eras, a few octillions of cubic leagues, 

do not hazard the span or make it impatient. 
They are but parts — anything is but a part, 
See ever so far, there is limitless space outside of that, 
Count ever so much, there is limitless time around that. 

— Walt Whitman. 



PRINCIPAL STARS AND PLANETS 

Name in parenthesis is constellation to which the star belongs. 

Achernar (Eridanus). A star of the first magnitude, 
eighth in order of brightness. Invisible in northern 
latitudes. Crosses meridian December 16th. Reced- 
ing at rate of ten miles per second. 

Albireo (Cygnus). A third dimension star in opposite 
extremity of constellation from Arided. Actually a 
double star. 

Alcor (Ursa Major). Companion star to Mizar. 

Aldebaran (Taurus). A star of the first magnitude, 
noted for its reddish tint. Its luminosity is about 
twenty-three times that of our Sun. Distant twenty- 
nine light years. Known as "the Bull's Eye." Re- 
ceding at rate of thirty miles per second. Distant 
thirty-two light years. 

Algol (Perseus). A famous variable star which waxes 
and wanes, decreasing in magnitude from 2.4 to 3.6. 
Algol forms part of the head of Medusa, which Per- 
seus is supposed to carry. 

Alkaid (Ursa Major). Epsilon, or fifth star in bright- 
ness in the "Dipper." Of the second magnitude. 
End of handle in "Dipper/' 

Alpha Andromedje (Andromeda). A double star of 
bluish-green tint and great brilliance. 2.5 to -5.5 
magnitude. 

Alpha Cassiopeia (Cassiopeia). A twin star, the 

245 



246 PRINCIPAL STARS 

brightest in this northern constellation, which is ac- 
tually a pair of blazing suns. Each is nearly the 
same size as our Sun. 

Alpha Centauri (Centaurus). A fine double star of the 
first magnitude, one being almost the counterpart of 
our Sun. Ranks third in order of brightness. In- 
visible in northern latitudes. Crosses meridian June 
29th. Approaching at rate of 13.8 miles per second. 
Distant four light years. 

Alpha Crucis (Crux). The brightest star in the South- 
ern Cross, but not visible in the northern latitudes. 
It is a triple star of 1.5, 1.8, and 6 magnitude. 
Crosses meridian May 29th. Receding at rate of 
4.3 miles per second. 

Alpha Perseii (Perseus). Brightest star in this eastern 
constellation. Set in a particularly fine star field. 

Alphecca (Corona). Brightest star in this constellation. 

Altair (Aquila). A brilliant star whose light is about 
eight times that of the Sun. Of first magnitude, and 
thirteenth in order of brightness. Crosses meridian 
September 19th. Approaching at rate of 20.5 miles 
per second. Distant sixteen light years. 

Andromeda Nebula (Andromeda). A nebular cluster of 
unusual beauty, and the brightest nebula in the heav- 
ens. 

Antares (Scorpius). A blazing red star about 3,000 
times as bright as our Sun. Of the first magnitude. 
Said to be even larger than Betelgeuse. 

Arcturus (Bootes). The brightest star in northern sky. 
Its light is 500 times that of the Sun; its velocity 
about 200 miles a second. Ranks fifth in order of 
brightness. Crosses meridian June 24th. Distant 
160 light years. 



PRINCIPAL STARS 247 

Bellatrix (Orion). A star of second magnitude in oppo- 
sition to Betelgeuse. 

Beta Cassiopeia (Cassiopeia). The right "pointer" at 
top of "W," which is used in determining Greenwich 
time. 

Beta Centauri (Centaurus). The tenth star in order of 
brightness, but invisible in northern latitudes. Crosses 
meridian June 21st. 

Beta Cyoni (Cygnus). An extremely beautiful double 
star. 

Betelgeuse (Orion). The brightest star in this constel- 
lation, and one of the largest known. Its mass is 
now reckoned to be 43 million times that of our Sun. 
Of the first magnitude, and eleventh in order of 
brightness. Crosses meridian February 15th. Reced- 
ing from the Earth at rate of thirteen miles per 
second. 

Canopus (Argus). Outranked only by Sirius in order of 
brightness. A first magnitude star, but invisible in 
our middle northern latitudes. Crosses meridian 
February 23rd. Receding from the Earth at rate of 
12.7 miles per second. 

Capella (Auriga). One of the brightest stars, and of 
first magnitude. Its mass is about 4000 times that of 
our Sun, and its luminosity 130 times as great. 
Ranks fourth in order of brightness. Crosses meri- 
dian February 5th. Receding from Earth at rate of 
19.7 miles per second. Distant thirty-two light years. 
Near Capella may be seen the "Three Kids." 

Castor (Gemini). A very fine double star. Magnitude 
2 and 2.8. Forms with Pollux the "Heavenly 
Twins." 

Ceres. A minor planet whose diameter is 480 miles. 



248 PRINCIPAL STARS 

Cor Caroli (Bootes). A fine double star named in honor 
of Charles II. 

61 Cygni (Cygnus). Famous as the first star whose 
distance was ever measured. Actually a double star, 
of 5.6 magnitude. Velocity sixty-three miles per sec- 
ond. Distant seven light years. 

Deneb (Cygnus). A star of the first magnitude, and 
about twentieth in order of brilliance. 

Dubhe (Ursa Major). Alpha, or brightest star in the 
"Dipper." Of the second magnitude. Dubhe and 
Merak are the "pointer" to the North Star, Dubhe 
being the nearer. 

Earth. Planet of our solar system. Third nearest the 
Sun. Distant 93 million miles. Yearly orbit 365 
days. Diameter 7913 miles. 

Eros. A minor planet with an elliptical orbit. 

Formalhaut (Piscis Australis). A star of the first magni- 
tude, ranking eighteenth in order of brilliance. 

Hamal (Aries). Brightest star in this constellation. Of 
second magnitude. 

Jupiter. Planet of our solar system. Distant 483 mil- 
lion miles from the Sun. Time of orbit twelve years. 
Size 1200 times that of the Earth. Diameter 92,000 
miles. 

Markab (Pegasus). One of four corner markers of this 
square. A second magnitude star. 

Mars. Planet of our solar system. Fourth nearest the 
Sun. Distant 141 million miles. Time of orbit 687 
days. Diameter 4230 miles. 

Merak (Ursa Major). Beta, or second brightest star in 
the "Dipper." Of the second magnitude. Forms 
with Dubhe the "Pointer" to the North Star, Dubhe 
being the nearer. 

Mercury. Planet of our solar system. Nearest the Sun. 



PRINCIPAL STARS 249 

Distant 36 million miles. Time of orbit eighty- 
eight days. Diameter 3030 miles. 

Messier 13 (Hercules). A fine star cluster which has 
been resolved by powerful telescopes into a group of 
5000 stars, some of them comparable to our Sun. 

Mizar (Ursa Major). A second magnitude star at the 
bend of the handle of the "Dipper." Near it may be 
seen a companion star, Alcor, of the fifth magnitude. 
Mizar itself is a twin star, radiating 115 times as 
much light as the Sun. Distant seventy-five light 
years. The two stars are 25 million miles apart. 

Nekkar (Bootes). A third magnitude star in the apex of 
this constellation, furthest removed from Arcturus. 

Neptune. Planet on extreme outer edge of our solar 
system. Distant 2790 million miles from the Sun. 
Time of orbit 165 years. Diameter, 34,000 miles. 

Orion Nebula (Orion). One of the finest nebular masses 
in the heavens. Appears as a hazy star to the unaided 
eye. 

Phad (Ursa Major). Gamma, or third brightest star in 
the "Dipper." Of the second magnitude. 

Pleiades (Taurus). A well-known cluster of bright stars, 
the central one being Alcyone. This group consists 
of seven stars, six being of the fourth magnitude; be- 
sides many of lesser brightness. The cluster crosses 
the meridian November 17th. The largest stars are 
100 to 200 times as bright as the Sun. 

Polaris (Ursa Minor). The Pole Star which gives us 
the due North of the heavens. Although not of the 
first magnitude, it is the most important of all, for this 
reason. Distant 47 light years. Around it all other 
stars and constellations appear to revolve. 

Pollux (Gemini). A star of the first magnitude. Com- 
panion to Castor, the two being known as the "Heav- 



250 PRINCIPAL STARS 

enly Twins." Receding at rate of 2.4 miles per 
second. 

Procyon (Canis Minor). One of our nearest star neigh- 
bors, and of the first magnitude. Its light is about 
ten times that of the Sun, its velocity eleven miles a 
second. Ranks ninth in order of brightness. Crosses 
meridian March 14th. Approaching at rate of 2.5 miles 
per second. Distant twelve light years. 

Regulus (Leo). A bright star of 1.2 magnitude. Its 
light is 1.000 times greater than our Sun. Approach- 
ing at rate of five miles per second. 

Rigel (Orion). A splendid star of the first magnitude 
which is 2,000 times as luminous as the Sun. Ranks 
seventh among the stars for brightness. Crosses 
meridian February 5th. Receding at rate of 13.6 
miles per second. On opposite side of constellation 
from Betelgeuse. 

Saturn. Planet of our solar system. Distant 886 mil- 
lion miles from the Sun. Time of orbit, twenty-nine 
and one-half years. Diameter, 74,000 miles. Noted 
for its rings. 

Scheat (Pegasus). One of four corner markers of this 
square. Of second magnitude. 

Sirius (Canis Major). The brightest star in the heavens. 
Magnitude 1.4. Although Sirius is only two and one- 
half times the mass of the Sun, it is thirty times as 
luminous. Crosses meridian February 28th. Ap- 
proaching at rate of 5.6 miles per second. Distant 
8.4 light miles. 

Spica (Virgo). A double star of the first magnitude. 
The components are about 11 million miles apart, and 
are about nine and six times the mass of the Sun re- 
spectively. Receding at rate of 1.2 miles per second. 

Uranus. Planet of our solar system, next to the farthest 



PRINCIPAL STARS 251 

removed. Distant 1780 million miles from the Sun. 
Time of orbit eighty-four years. Diameter, 31,000 
miles. 

Vega (Lyra). A star of first magnitude, and sixth in 
order of brilliance. About 100 times as radiant as 
our Sun. Crosses meridian August 30th. Approach- 
ing at rate of 8.5 miles per second. Astronomers 
reckon that it will become the North Star, 12,000 years 
hence. Distant twenty-seven light years. 

Venus. Planet of our solar system. Second nearest to 
the Sun. Distant 67 million miles. Time of orbit 225 
days. Diameter 7799 miles, or nearlv the size of the 
Earth. 



GLOSSARY 

Aerolite. A mass or fragment falling from celestial space 
to the earth. During its flight it is called a meteor, 
and its fragments are meteorites or aerolites. 
Aphelion. The point in space on the orbit of a planet 
or comet, when it is the furthest removed from the 
Sun. Reverse of perihelion. 
Arc. A portion of the path of a heavenly body. A curve 

or part of a circle. 
Asteroids. A group of small planets, or planetoids, revolv- 
ing around the Sun. There are several hundred of 
these, and their diameters are usually less than 100 
miles each. 
Astronomy. That science which treats of the heavenly 
bodies, their size, orbit, distance, and relation to each 
other. 

Aurora Borealis. The northern lights, or the glow which 
is often seen in the sky at the far north. Now be- 
lieved to be electrical in origin. 

Axial motion: That motion of a planet or other body 
around its axis, or common center. 

Axis. An imaginary line through the center of a body, 
around which it revolves. The Earth's axis passes 
through its center from Pole to Pole. 

Binary Stars. A pair of stars revolving around a common 
center of gravity. 

Bolide. A shooting star or meteor, of unusual brilliance. 

Centrifugal Force. A force pulling away from the 

253 



254 GLOSSARY 

center of a body. The reaction or pull against a force 
tbat is causing a body to move in a circle. 

Chromosphere. A sphere or layer of red gases surround- 
ing the Sun. Visible during an eclipse. 

Coma. The nebulous mass surrounding the head or nucleus 
of a comet. 

Comet. A heavenly body noted for its singular appear- 
ance and eccentric orbit. It usually consists of a 
bright star-like nucleus, with a train of great length. 

Conjunction. The nearest point of approach of two 
heavenly bodies to each other, as viewed from the 
Earth. 

Constellation. A fanciful grouping of certain neighbor- 
ing stars to form a figure or picture. As the constel- 
lation of Ursa Major comprises 7 stars said to resemble 
a bear or dipper. 

Constellations of the Zodiac. The constellations or 
signs of the zodiac are 12 different groups of stars, one 
for each month, as determined originally by the fact 
that such constellation was in the zenith on a given 
month. 

Copernican Theory. The accepted astronomical system, 
first advanced by Copernicus in 1543, which makes the 
Sun the center around which the Earth and other 
planets revolve. 

Corona. The circle of light radiating from a celestial 
body. Specifically, the Sun's corona is the mass of 
rays seen shooting from it in every direction, during 
an eclipse. 

Crescent Moon. The visible portion of the Moon in its 
first or last quarter. Consequently, the term to denote 
a new moon, or one in its last days. 

Crepe Ring. A semi-transparent ring around Saturn — • 
one of three rings, the other two being bright. 



GLOSSARY 255 

Degree. A 360th part of a circle or circumference. A 

ninetieth part of a right angle. Thus from due north 

to due east is a rectangle, and one degree is a 90th 

part of that distance. 
Displacement. The apparent change of position of a 

heavenly body from its true course. 
Double Star. Two stars so closely associated as to appear 

to be one, to the naked eye. 
Earth-shine. The faint light visible on the dark part of 

the Moon when it is new, and caused by reflection of 

light from the Earth. 
Eastward. Running in an easterly direction, or at a right 

angles to the line of the North Star. 
Eclipse. The obscuring of one heavenly body by another 

in the same line of vision — as the eclipse of the Sun 

by the passage of the Moon across its field. 
Ecliptic That plane, passing through the center of the 

Sun, which contains the Earth's orbit. 
Ellipse. The path of a planet around the Sun, which may 

be popularly described as an oval or a flattened cir- 
cle. 
Equator. The imaginary line passing around a planet at 

its widest part, and equidistant from its Poles. 
Equinox. One of two opposite points in the heavens where 

the Sun's position in regard to the Earth causes days 

and nights of equal length. 
Evening Star. The bright planet visible in the West just 

after sunset, and before any stars are visible. 
Faculae. Small spots on the Sun which are brighter than 

the rest of the photosphere. 
First Quarter. The first of the four phases through 

which the Moon passes each month, and in which it 

appears as a crescent, then a quarter-filled circle. 
Fixed Star. A celestial body shining with its own light, 



256 GLOSSARY 

and so far removed from our own solar system that its 

relative position seems unchanged. 
Galaxy. A luminous band of star clusters. Usually 

applied to the Milky Way. 
Gegenschein. A faint luminous spot which may be seen 

on the ecliptic ninety degrees away from the Sun. 

Also called the zodiacal afterglow. 
Gibbous. Rounded or swelling. A gibbous moon is one 

that is between half full and full. 
Gravitation. The constant force or pull exerted between 

two bodies in space; also the tendency of all loose 

particles on any heavenly body to fall toward its 

center. 
Grimaldi. A large plain on the surface of the Moon, said 

to contain 14,000 square miles. 
Harvest Moon. The full moon occurring about the time 

of the autumnal equinox, which rises about the same 

time for several nights in succession. 
Heliometer. An instrument used in measuring angles and 

distances between heavenly bodies. A specially con- 
structed telescope whose objective may be cut into 

two parts. 
Horizon. The point of one's vision where the earth and 

sky meet. The furthest point in any direction by land 

or sea, where the sky cuts off the view. 
Hunter's Moon. Name given to the full Moon occurring 

in October. 
Inclination of the Earth's axis. A leaning away from 

the upright, or from a right angle. The dip away 

from an upright position in the Earth's orbit, causing 

its axis to point to the north star. 
Inner Planets. Name given to the four planets which 

are nearest the Sun — Mercury, Venus, Earth, and 

Mars. 



GLOSSARY 257 

International Date Line'. The 180th meridian, or the 
one on the opposite side of the globe from the Green- 
wich Observatory, crossing the Pacific Ocean. Here 
time is set forward or back one day, according as one 
is traveling West or East. 

Last Quarter. The fourth of the Moon's phases, when it 
is again approaching crescent shape and reaching "the 
dark of the Moon.'* 

Light Pressure. A constant repellent force which is 
exerted by the Sun's rays, but is felt only upon the 
lightest bodies, such as the tail of a comet, causing it 
always to point away from the Sun. 

Light-sphere. The radiant envelope of gases surround- 
ing the Sun. 

Light Year. A term used by astronomers to denote ex- 
treme distances. Light travels 180,000 miles per 
second, and in one year would travel nearly seven and 
one-half billion miles. 

Magnitude. An arbitrary scale for measuring the bright- 
ness of stars, the brightest (twenty in number) being 
of the first magnitude, and the faintest, as seen by the 
unaided eye, the sixth. 

Mean Solar Day. The average length of the total num- 
ber of days as seen in a transit around the Sun. The 
common measure of time. 

Meridian. The line in the heavens running north and 
south and passing directly overhead. The vertical 
plane parallel to the Earth's axis. 

Meteor. Name given to a small heavenly body flying 
through space which suddenly strikes the Earth's 
atmosphere and becomes luminous. 

Meteorite. A mass of stone, iron, or other metal which 
has fallen to the Earth from the outer realms of space. 

Midnight. The middle of the night — twelve o'clock — 



258 GLOSSARY 

when the Sun is on the opposite side of the Earth. 

Mile. The unit of measure for long distances in English- 
speaking countries. One-sixtieth of a degree of the 
Earth's surface at the equator. In America, 5280 
feet. 

Milky Way. Also called the Galaxy, the Milky Way is 
the broad band or bands of hazy star clusters and 
nebulae stretching across the heavens. 

Minute. In time, the sixtieth part of an hour. In astron- 
omy, the sixtieth part of a degree. 

Moon. A celestial body revolving around the Earth once 
in about 27 days, 8 hrs. Its satellite. The name, 
moon, is also applied to the satellites of other planets. 

Morning Star. The planet which is conspicuous in the 
eastern sky just before dawn. Jupiter, Mars, Saturn, 
or Venus. 

Neap Tides. The tides occurring just after the first and 
third quarters of the Moon, when its attraction upon 
the sea is weakest. 

Nebula. In astronomy, an unformed mass of stellar 
substance, which is believed to be stars and planets in 
the making. 

Nebular Hypothesis. The theory advocated by Kant, 
Herschel and others, that our solar system was origin- 
ally a nebula which as it cooled and contracted formed 
the Sun and its planets. 

New Moon. The first phase of the Moon, in which it 
appears as a thin, bright crescent. 

Node. The point where the orbit of a heavenly body cuts 
across the ecliptic. The intersection on the celestial 
sphere of any two circles, such as the equator and the 
ecliptic. 

Nucleus. A head or center. The nucleus of a comet is 
the bright point from which the tail streams. 



GLOSSARY 259 

Occult. To cover from view or conceal. In an eclipse, 
one heavenly body occults another. The Moon con- 
tinually occults the stars behind it. 

Opposition. The point at which two heavenly bodies are 
furthest removed from each other, or their longitudes 
differ by 180 degrees. Thus there is an opposition of 
the Sun and Moon at every full moon. 

Optical Doubles. Two stars which appear double to the 
unaided eye because they are in the same angle of 
vision, though perhaps many millions of miles apart. 

Orbit. A path or track. In astronomy it alludes to the 
path in space along which a heavenly body travels. 

Outer Planets. The four planets furthest removed from 
the Sun — Jupiter, Saturn, Uranus, Neptune. 

Parabola. A curve commonly described as the intersec- 
tion of a cone with a plane parallel with its side; the 
two sides of which constantly diverge. 

Parallax. The difference between the apparent position 
of a heavenly body if viewed from the Earth's center 
and from a point on its surface. 

Parallels. Lines lying in the same plane which remain 
the same distance from each other. 

Perihelion. The point in the orbit of a planet or other 
body when it is nearest the sun. The reverse of 
aphelion. 

Phases of the Moon. The aspects or changes which the 
Moon assumes, beginning as a narrow crescent, pro- 
ceeding to full, and waning to another crescent. 

Photosphere. The radiant surface, which is visible to 
Earth inhabitants, of the Sun; also of fixed stars. 

Planets. Specifically applied to the eight members of our 
solar system, bodies which revolve around the Sun and 
receive their light and warmth therefrom. These are: 
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, 



260 GLOSSARY 

and Neptune. Besides these there are many small 
planets or planetoids. 

Planetesimal Hypothesis. Opposed to the nebular 
hypothesis, this theory is that our solar system was 
created from a central sun surrounded by planetoids 
and nebula, from which were successively created our 
Sun and its satellites. 

Planetoids. Minor planets or asteroids. Several hun- 
dred such bodies have been discovered in our solar 
system, lying chiefly in the vast field between Mars 
and Jupiter. 

Polar. Pertaining to a pole, or the extremity of an 
imaginary line or axis passing through the Earth or 
other celestial body. 

Precession of the Equinoxes. A slow motion of points 
of the equinox on the ecliptic from east to west, at the 
rate of about fifty degrees annually — thus changing 
the time at which constellations are visible. 

Prominences. Flashes of light or eruptions of gas above 
the chromosphere of the Sun. These are beautifully 
colored, fantastically shaped, and often thousands of 
miles high. 

Ptolemaic Theory. Ptolemy, an Alexandrian astronomer, 
published about 140 a. d., an "Almagest," in which he 
assumed that the Earth was the center of our system, 
and around it the other heavenly bodies revolved. 

Quarter Moon. One of the four phases through which 
the Moon passes in its monthly waxing and waning. 

Retrograde. The backward movement which the Earth 
appears to have, relative to the fixed stars. 

Rills. Deep and wide crevices which are visible upon the 
surface of the Moon. 

Satellite. A smaller body which revolves around or is 



GLOSSARY 261 

attracted by a larger one. The best example is the 

Moon, which is the Earth's satellite. 
Shift. The apparent displacement of a star on the back- 
ground of the sky, when viewed from different angles. 
Shooting Stars. Popular name given to meteors, or 

wandering bodies which strike our atmosphere and 

become luminous. 
Sidereal Day. The exact time required by the Earth to 

make a complete turn on its axis, as measured by the 

stars. 
Sidereal Period. Time as measured by the apparent 

motion of the stars, as opposed to that measured by 

the Sun. 
Signs of the Zodiac. The names given to twelve con- 
stellations on account of their fancied resemblance to 

certain figures. See Zodiac. 
Solar Cycle. A seven-year period during which the spots 

on the Sun increase and decrease. 
Solstice. The time of year when the Sun pauses and then 

turns back on its apparent course — usually on June 

21st, which is the longest day, and December 22nd, 

which is the shortest day in northern latitudes. 
Spectroscope). An optical instrument for determining and 

measuring the various rays emitted by the Sun and 

other luminous bodies. 
Spectrum. An image formed by rays of light, and usually 

seen as parallel bands of varying colors. 
Spring Tide. The high tide which occurs twice each 

month due to the combined attraction of the Sun and 

Moon. 
Star. Name given to distant celestial bodies, many of 

which are larger than our Sun, the latter being itself a 

star. 



262 GLOSSARY 

Star Cluster. An apparent close grouping of star masses 
partly due to their revolution around a common center, 
and partly the result of their great distance from the 
eye. 

Sun. Name given to any glowing and light-emitting 
heavenly body. In addition to the Sun which is the 
center of our solar system, there are many other suns 
among the fixed stars. 

Synodic Period. The interval of time which elapses be- 
tween the conjunctions of two heavenly bodies. 

Tail (of Comet.) A nebulous mass extending from 
the head of a comet, always in a direction away from 
the Sun. 

Temporary Stars. Stars which wax and wane and some- 
times disappear from view altogether. Thought to be 
due to friction caused by contact with the nebulous 
masses. 

Transit. The act of passing across a field of vision, as 
for example the transit of Venus across the face of 
the Sun. 

Uranolith. A meteorite; a small wandering heavenly 
body which shatters on encountering the Earth's 
atmosphere. 

Variable Star. A star which varies in light-giving prop- 
erties, due it is thought to obscuration by another star, 
or explosions of gas. 

Vernal Equinox. The period in the spring when the Sun 
crosses the Equator and the days and nights are of 
equal length. Usually March 21st. 

Year of Time. The time required for a given planet to 
make one revolution around the Sun. 

Zenith. The point in the celestial sphere that is exactly 
overhead, or at an angle of ninety degrees from the 
Earth's plane. 



GLOSSARY 263 

Zodiac. An imaginary zone or girdle stretching around 
the celestial sphere and extending eight degrees on 
each side of the ecliptic. It is the path followed by 
the Moon and all of the planets across the sky. It is 
divided into twelve parts, one for each month, and 
marked by a certain constellation, called a "sign of 
the zodiac." 

Zodiacal Light. A disk of faint light surrounding the 
Sun, lying near the plane of the ecliptic and extend- 
ing beyond the Earth's orbit. 



INDEX 



Adams, English student of 
astronomy, discoverer of 
Neptune, 116-117 

Aerolites. See Meteorites 

Air, composition of, 65 

Airy, Sir George, English 
Royal Astronomer, 116 

Albireo, double star, 227 

Alcor, star, 206 

Alcyone, star, 15; in the Plei- 
ades, 214 

Aldebaran, star, 10; movement 
of, 14; a member of Hyades 
group, 215-216 

Algebar (Rigel), star, 217 

Algol, variable star, 212-213 

Alpha, star, 234; in constella- 
tion of Libra, 237 

Alpha-Centauri, 3, 4; distance 
from Earth, 9; a binary star, 
184 

Alps, on Moon, 123 

Altair, star, 239 

Andromeda, constellation, 173; 
Great Nebula in, 159-160, 162, 
212 

Andromedids, meteoric shower 
called, 173 

Annular nebulae, significance of 
term, 161 

Antares, star, 11, 12, 237; com- 
panion of, 186 

Apennines, on Moon, 123 

Aphelion, planets at, 94 

Aquarius, how to locate, 240 

Aquila, constellation, 211, 225* 
226 

Archer. See Sagittarius 

Archimedes, crater on Moon, 
123 



265 



Arc-lights, explanation of, 39- 
40 

Arcturus, star, 10, 223; move- 
ment of, 13 

Aries, constellation, 234 

Aristotle, theory of Universe 
taught by, 47; theory of, con- 
cerning Milky Way, 193 

Asteroids, minor planets, 67, 
68; diameter of, 69; first dis- 
coveries of, 100-103; later 
discoveries and number of, 
103-104; improbability of liv- 
ing beings on, 104; slight in- 
formation about, 105-106; 
origin of, 106 

Astronomy, science of, 3-4 

Atmosphere, of Earth, 65-66 

Auriga, the Charioteer, con- 
stellation, 110, 213 

Aurora borealis, relation be- 
tween sun-spots and, 35 

Autumn, season of, 60 

Axis of Earth, 52; inclination 
of, 52-53 

Balance. See Libra 

Ball, Sir Robert, cited, 4; 
quoted on distance of Sun, 
25-26; on planets, 76; on 
weight of planet Mercury, 84- 
87; on Venus, the evening 
star, 87-88; on life on aster- 
oids, 104-105; on annular 
nebula in Lyra, 161-162; on 
shooting stars, 170; on mete- 
orites, 178-179; on results of 
extinction of Sun, 194-195 

Barnard, E. E., quoted on rifts 
in Milky Way, 196 



266 



INDEX 



Beehive, star group called, 189 

Bellatrix, star, 217 

Beta-Cassiopeia, star, 55 

Beta-Cygni, double star, 186 

Betelgeuse, star, 11, 217 

Bible, theory of creation in, 44, 
45-46 

Biela's comet, periods of, 153- 
156 

Bielid meteoric shower, 175 

Big Dipper, constellation, 14; 
position of, 203-204; with 
Pole Star, forms Great Star 
Clock of the North, 207-208 

Binary stars, term for double 
stars, 184 

Bode, German astronomer, and 
his law, 100-101 

Bolides. See Meteors 

Bootes, the Herdsman, con- 
stellation, 10, 211, 222 

Bruno, G., scientist, 50 

Bryant, W. C, Hymn to the 
North Star, quoted, 203 

Bull, constellation, 211 

Calcium, element of Sun, 40 
Callisto (IV), moon of Jupiter, 

110 
Callisto, star in Great Bear, 

205 
Canals, discovery of, on Mars, 

96 
Cancer, constellation, star clus- 
ter in, 189; how to locate, 

234-235 
Canis Major, constellation, 211. 

See Sirius 
Canis Minor, 220 
Capella, star, 11, 110, 213 
Capricornus, constellation, 234, 

238-240 
Carbon, Sun's energy stored in, 

39-40; in comets, 137 
Carbon dioxide in air, 65 
Cardinal points, establishment 

of, 57 
Carnegie Solar Observatory, 

California, 39 



Carpathian Mountains on 
Moon, 123 

Cassiopeia, constellation, 55 ; 
location of, 208 

Castor, double star, 184-185 

Castor and Pollux, 220-222 

Ceres, minor planet, 101-102 

Chambers, quoted on annular 
nebulae, 161 

Charles II, observatory at 
Greenwich founded by, 223 

Charles's Wain, Big Dipper 
called, 204 

Chromosphere of Sun, 39 

Clerke, Miss, System of the 
Stars, quoted, 160-161, 195- 
196 

Coal, explanation of, 23-24 

Colored stars, 182 

Colors of planets, 77 

Coma of comet, 137 

Comet chips, 156-157 

Comets, 84; derivation of name, 
135; early theories concern- 
ing, 135-136; modern dis- 
coveries concerning, 136 ; 
three parts of, 137; composi- 
tion of, 137; distinguishing 
from nebulae and planets, 
140-141; irregular movements 
of, 141; speed of, 141-142; 
number of, 142; problems 
presented by, 142-144; forms 
of path possible to, 144-145; 
identification of, 145-147; 
chances of Earth colliding 
with, 149-151; fascination of 
Sun for, 152-153; searching 
for, an interesting occupa- 
tion, 156; residue of, or 
comet chips, 156-157; mete- 
ors found to be chips and 
dust particles of, 175 

Conjunction, planets in, 81; 
almanac sign to show, 81 

Constellations, derivation of 
word, 201; arrangement of 
stars into, by early Greeks 
and other peoples, 201-202; 
Big and Little Dippers, 203- 



INDEX 



267 



208; Cassiopeia, 208; sugges- 
tions for tracing, 209; move- 
ment of, 210-211; some of 
principal, 211-228; the zodia- 
cal, 228-241; host of unmen- 
tioned, remaining, 241-242 

Copernicus, crater on Moon, 
123 

Copernicus, Nicolaus, solar 
theory of, 49-50; moons of 
Jupiter proof of theory of, 
110; quoted on comets, 135 

Cor Caroli, double star, 222 

Corona of Sun, 37-38 

Coronium, element of Sun, 40 

Crab. See Cancer 

Creation, ancient theories of 
the, 44-49 

61 Cygni, star, 9-10, 227; move- 
ment of, 13 

Cygnus, constellation, 211, 226 

Day, sidereal and mean solar, 
55-57; longest and shortest, 
60 

Deimos, satellite of Mars, 98- 
99 

Delta-Lyrae, star, 14 

Directions, system of, estab- 
lished bv rotation of Earth, 
57 

Displacement of a star, 7-8 

Doerfel range on Moon, 123 

Dog days, derivation of term, 
219 

Dog Star. See Sirius 

Double-double, quadruple star 
called, 225 

Double stars, colored and, 182- 
190; Mizar and Alcor, 206 

Draco, nebula in, 164 

Dust, meteor, 170 

Eagle. See Aquila 

Earth, ancient conception of, 2- 
3; real facts about, 3; meas- 
urement of distance of stars 
from, 6-11; comparative size 
of, 11; life on, dependent on 
Sun, 23-25; weight of Sun 



and, compared, 27-28; orbit 
of, 42; distance from Sun, 42; 
creation of, 44-47; ancient 
and medieval theories con- 
cerning, 47-50; law of grav- 
itation and motion of, 51-52; 
speed of, around annual or- 
bit, 52; rotation of, on its 
axis, 52-55; measurement of 
time by rotation of, 55-57; 
system of establishing direc- 
tions suggested by rotation 
of, 57-59; change of seasons 
caused by revolution of, 59- 
G2; composition, weight, and 
dimensions of, 62-64; atmos- 
phere of, 65-66; an inner 
planet, 68; diameter of, 69; 
velocity of, 70; distance of 
other planets from, 72; period 
of revolution of, 72; theory 
of Moon as daughter of, 120- 
122; comets and^the, 149-152; 
fall of meteors and meteor- 
ites on, 170-173, 175-176, 177- 
181 
Earth-shine on Moon, 127 
Eclipses, 37; dates of, 37-38 
Edison, T. A., on wireless sig- 
nals from other planets, 90-91 
Einstein, A., on communication 

with other planets, 97 
Encke's comet, 84-87; period 

of, 146 
Equinox, spring or vernal, 59, 

62; autumnal, 60 
Equinoxes, precession of the, 

215 
Eratosthenes, point on Moon, 

120 
Ericsson, John, inventor, 31 
Eros, asteroid, 98, 103-104 
Europa (II), moon of Jupiter, 

110 
Evening stars, planets called, 
77 

Faculas on Sun, 36 

Fire-balls, 156 

Fire mist. See Nebulae 



268 



INDEX 



Fishes. See Pisces 

Fish-mouth Nebula, the, 159 

Fixed stars, 12-13; distinguish- 
ing planets from, 76-79 

Flammarion, C, quoted on velo- 
city of planets, 71; on rings 
of Saturn, 112 

Formalhaut, star, 241 

Galaxy, the, 192. See Milky 
Way 

Galileo, sun-spots discovered 
by, 34; persecution of, 50; 
telescope invented by, 107; 
discovery of moons of Jupi- 
ter by, 110; investigation of 
Milky Way by, 193 

Ganymede (III), moon of Jupi- 
ter, 110 

Gegenschein, counter-glow of 
zodiacal light, 171 

Gemini, constellation, 184, 211, 
220-221 

Gibbous moon, 126 

Goat. See Capricornus 

Gore, quoted on Mercury, 82; 
on the Milky Way, 193; on 
number of stars and systems, 
198-199 

Gravitation, law of, 51 

Great Bear, ancient name for 
Big Dipper, 204 

Great Northern Constellation, 
208-209 

Great Square of Pegasus, con- 
stellation, 211-213 

Great Star Clock of the North, 
207-208 

Greeks, planets named by, 47- 
48; early geographers of 
heavens, 201 

Gregory, David, quoted on size 
of Sun, 27 

Grimaldi, plain on Moon, 129 

Halley's comet, period of, 146; 

account of, 147-149 
Harvest Moon, the, 128 
Heavenly Twins. See Gemini 



Helium, element of Sun, 40; in 

nebulae, 158-159 
Hercules, constellation, 211; 

star cluster in, 189-190 
Herdsman. See Bootes 
Herschel, Sir John, "The Jew- 
eled Cluster" named by, 186 
Herschel, Sir W., discoverer of 
Uranus, 114; theory of neb- 
ulae formulated by, 158; 
cited on colored and double 
stars, 183-184 
Hipparchus, Greek astronomer, 

18 
Hoedi, or three kids, stars, 213 
Hunter's Moon, the, 128 
Hyades group of stars, 216 
Hydrogen, element of Sun, 40; 
in nebulae, 158, 163-164 

Inclination of Earth's axis, 52 
International Date Line, 58-59 
Io (I), moon of Jupiter, 110 
Iron, element of Sun, 40; in 

comets, 137 
Isaiah, prophet, quoted, 20 

Jeweled Cluster, the, 186 
Juno, minor planet, 103 
Jupiter, planet, 41; distance 
from Sun, 42-43; size of, 
compared with Earth, 43; 
derivation of name, 48; an 
outer planet, 68; diameter 
of, 69; moons of, 70, 109-110; 
velocity of, 70; period of 
revolution of, 72; color of, 
77 ; special characteristics 
of, 106-108; a world in the 
making, 108; weight of, 108- 
109; comets about, 146 

Kelvin, Lord, cited on solidity 

of Earth, 64 
Kepler, J., early astronomer, 

20; persecution of, 50; on 

comets, 135 
Kneph, Star of, 219 

Langley, S. P., cited on inten- 
sity of sunlight, 33 



INDEX 



269 



Latitude and longitude, meas- 
urement of, 57-59 

Ledaean lights, Castor and Pol- 
lux called, 221 

Leibnitz range on Moon, 123 

Lelande, blundering astrono- 
mer, 117 

Leo, constellation, 173, 211; 
how to locate, 235 

Leonids, meteoric shower called, 
173 

Le Verrier, French astronom- 
ical student, discoverer of 
Neptune, 115-116 

Libra, constellation, 236-237 

Light pressure exerted by Sun, 
139 

Light ray, communication with 
other planets by the, 97 

Light year, unit for measur- 
ing star distances, 9 

Little Bear (Little Dipper), 
204-207 

Little Dog, constellation, 220 

Longfellow, H. W., Golden Le- 
gend, quoted, 222 

Lowell, Percival, interest of, 
in Martian canals, 96-97 

Luzon, eclipse of, 38 

Lyra, constellation, 14, 173, 224- 
225; annular nebula in, 161- 
162 

Lyrids, meteoric shower called, 
173 

Macpherson, H., Jr., Ro- 
mance of Modern Astronomy, 
quoted, 2-3, 12-13, 47; on co- 
rona of Sun, 37; on distance 
of planets from Sun, and 
size, 68-69; on weight of ob- 
jects on different planets, 74- 
75; on the Universe seen 
from Mars, 99-100; on Nep- 
tune, 118 

Manger, cluster of stars, 234- 
235 

Man in the Moon, 128 

Marconi, W., quoted on wire- 



less signals from other plan- 
ets, 89-90 

Mars, size of, 41; orbit of, 42; 
derivation of name, 48; an in- 
ner planet, 68; diameter of, 
69; satellites of, 70; distance 
from Earth, 72; period of 
revolution of, 72; color of, 
77; special attention claimed 
by, 92-93; dimensions and 
other details, 93-95; question 
of inhabitants on, 95-96; 
canals on, 96-97; satellites 
of, 97-99; view of Universe 
from, 99-100 

Mercury, planet, 10; size of, 41; 
orbit of, and distance from 
Sun, 42; derivation of name, 
48; an inner planet, 67; di- 
ameter of, 69; velocity of, 
70, 71; period of revolution 
of, 72; color of, 77; location 
of, 79-81 ; general character- 
istics of, 81-83; the smallest 
and lightest planet, 83-84; 
story of Encke's comet and, 
84-87; transit of, 91 

Meredith, Owen, The Wander- 
er, quoted, 221 

Meridians, establishment of, 
57; used for determining 
time sections, 57-58 

Messier, discoverer of comets, 
156 

Messier 13, star cluster, 189- 
190 

Meteorites, 156, 177; two 
classes of, 177-178; early the- 
ories regarding, 178-179; 
some notable, 179-180 

Meteors, 156; wrongly called 
shooting stars, 169; number 
of, 170; groups of, and 
months when most seen, 171; 
speed of, 172; showers of, in 
heavens, 173; investigations 
of orbit and origin of, 173-176 

Midnight Sun 3 phenomenon of, 
53-54 



270 



INDEX 



Milky Way, composition of, 15- 
16; poetic conceptions of, 
191-192; scientific theories re- 
garding, 192-195; extent and 
appearance of, 195-196; sig- 
nificance of rifts in, 196; the 
Sun a possible member of, 
197 

Milton, John, quoted, 191, 238 

Mimas, moon of Saturn, 113 

Mitton, G. E., The Book of 
Stars, quoted, 175-176; quoted 
on multiple systems of stars, 
185-186 

Mizar, star, 206 

Months, origin of, in zodiacal 
division, 229 

Moon, ancient conception of, 
2-3; eclipses of, 37; old the- 
ories concerning, 47-50; ap- 
plication of laws of gravita- 
tion and motion to, 51-52; 
distance from Earth, 119-120; 
geography of, 120; theory of 
formation of, 120-122; char- 
acteristics of, 122; seas, 
mountains, and craters of, 
122-124; movements of, 124- 
125; phases of, 125-127; rate 
of movement of, 127-128; 
configurations on surface of, 
128-129; reckoning time by, 
129-130; tides produced by, 
130; imagined conditions on, 
130-134 

Moons, of planets, 69-70; of 
Mars, 97-99; of Jupiter, 109- 
110; of Saturn, 112-113 

Morning stars, planets called, 
77 

Motion, laws of, discovered by 
Newton, 51-52 

Motors, solar, 31-32 

Mountains of Moon, 123 

Napoleon, attempt to give 
name o'f, to star group, 217- 
218 

Nebulae, confusion of, with com- 
ets, 140; peculiar interest at- 



tached to, 158; early theories 
regarding, 158 ; Herschel's 
explanation of, 158-159; two 
famous, in Orion and in An- 
dromeda, 159-160; number 
of, 160; shapes and sizes, 160- 
161; classification, 161-162; 
distance from Earth, 162-163; 
composition of, 163-164 

Nebular hypothesis, 76; state- 
ment of, 165-166 

Neptune, planet, 11, 18; size of, 
41; distance from Sun, 43; 
an outer planet, 68; diame- 
ter of, 69; satellite of, 70; 
velocity of, 70, 71; period of 
revolution of, 72; color of, 
77; discovery of, 115-116; ac- 
count of, 116-118; comets 
about, 146 

Newcomb, S., Astronomy for 
Everybody, quoted, 64-65; on 
size of moons of Mars, 98 

Newton, Isaac, discoveries of, 
50-51; theory of, that comets 
have orbits, 136 

Nickel, element of Sun, 40 

Nile star, Sirius called, 219 

Nitrogen in air, 65 

Northern Cross, stars which 
form, 226-227 

Northern Crown, cluster of 
stars, 223-224 

North Pole, apparent motion 
of Sun as seen from, 54-55 

Nucleus of comet, 137 

Occultation of star by Moon, 
129 

Olbers, H., discovery of Pal- 
las by, 102 

Opposition, planets in, 80; al- 
manac sign showing, 81 

Orbits, of planets, 42; of 
meteors, 173-176 

Orion, constellation, 11, 12-13, 
211; Great Nebula in, 159; 
location of, 216-218 

Ossian, extract from, 21 



X 



INDEX 



271 



Oxygen, in air, 65; importance 
of, 65-66 

Pallas, minor planet, 102 
Parallax, defined, 7; use of, 7- 

8 
Parallels, establishment of, 57 
Peary, R. E., meteorite dis- 
covered by, 179-180 
Pegasus, Great Square of, 234 
Perihelion, planets at, 93 
Periods, synodic and sidereal, 

of Moon, 125 
Perrier, E., picture of Mar- 
tians by, 95 
Perseids, meteoric shower 

called, 173 
Perseus, constellation, 15, 173, 

211 212 
Phase's of Moon, 125-128 
Phobos, satellite of Mars, 98- 

99 
Phoebe, moon of Saturn, 112- 

113 
Photography, locating planets 

by, 78 
Photosphere, defined, 33-34 
Piazzi, G., discovery of Ceres 

by, 101-102 
Pisces, constellation, 211; how- 
to locate, 240-241 
Planetesimal hypothesis, 76 ; 

statement of, 166-167 
Planetoids. See Asteroids 
Planets, 41 ; derivation of word, 
47; named by Greeks, 47-48; 
old theories concerning, 48-50 ; 
laws of gravitation and mo- 
tion as affecting, 51-52; divi- 
sion into inner and outer, 67- 
68; table of diameter of, 69; 
velocities of, 70-72; periods 
of revolution around sun, 72; 
weight of articles on, 73-75; 
theories concerning origin of, 
76; distinguishing from fixed 
stars, 76-79 
Plato, crater on Moon, 123 
Pleiades, constellation, 15, 213- 



215; a star group, 188-189; 
derivation of name, 215 

Plow, the, 13; one name for 
Big Dipper, 204 

Pointers, stars in Big Dipper, 
204, 207, 208 

Pole Star, 10, 202-203; posi- 
tion of, 203; center of Great 
Star Clock of North, 207-208 

Pons, discoverer of comets, 156 

Precession of the equinoxes, 
215 

Proctor, R. A., quoted on the 
Sun, 43; on colored and 
double stars, 188 

Prominences of Sun, 37-39; 
height, duration, and color 
of, 39 

Ptolemy, theory of Universe of, 
48-49 ; constellations re- 
corded by, 201 

Ptolemy, crater on Moon, 123 

Rainfall, cause of, 65 
Ram. See Aries 
Regulus, star, 235 
Retrograde, motion in, 115 
Rigel, star, 11, 217 
Rills on Moon, 124 
Rings, Saturn's, 111-112 

Sagittarius, constellation, 237- 

238 
Sahara, eclipse of, 38 
Saint Elmo's lights, 221 
Satellites of planets, 69-70 
Saturn, planet, 41; distance 
from Sun, 42-43; derivation 
of name, 48; an outer planet, 
68; diameter of, 69; satellites 
of, 70; velocity of, 70; period 
of revolution of, 72; color of, 
77; special characteristics of, 
110-111; rings around, 111- 
112; moons of, 112-113; light 
weight of, 113-114; in an 
early stage of development, 
114; comets about, 146 
Scheiner, one of discoverers of 
sun-spots, 34 



272 



INDEX 



Schiaparelli, quoted on the Sun, 
43; discovery of canals on 
Mars by, 96 

Schmidt, Johann, chart of Moon 
by, 120 

Schwabe, astronomer, 35 

Scorpio, constellation, 11, 186, 
211, 237 

Seasons, phenomenon of change 
of, 23; caused by Earth's rev- 
olution around Sun, 59-62; 
constancy in variation of, 62 

Serviss, Garrett P., quoted, 10- 
11; on the Milky Way, 16; 
on star cluster "Messier 13," 
189 

Seven Sisters. See Pleiades 

Shooting stars, 155; a mislead- 
ing term, 169. See Meteors 

Sidereal time, 55-57 

Signs of zodiac, distinguished 
from constellations of zodiac, 
231-232 

Sirius, the Dog Star, 10, 211, 
218-220; a double star, 184 

Sodium, element of Sun, 40; in 
comets, 137 

Solar cycle, discovery of, 35 

Solar motors, use of, 31-32 

Solar system, 41-43 

Southern Cross, constellation, 
227-228 

Southern Fish, constellation, 
241 

Spectroscope, use of, 12, 14, 17, 
40, 115; for studying promi- 
nences of Sun, 38-39; compo- 
sition of nebulae revealed by, 
159 

Spica, constellation, 236 

Spring, cause of, 59-60 

Stars, account of, as suns, 1-2; 
study of, 3-4; estimates of 
number of, 4, 12, 197-198; 
measuring distance of, from 
Earth, 6-11; size of, 11-12; 
movement of, 12-13; direction 
of movement, 14-15; in Milky 
Way, 15-16; temporary, 16- 
19; variable, 19; distinguish- 



ing planets from fixed, 76-79 ; 
colored and double, 182-190; 
designations used for indicat- 
ing brightness or magnitude 
of, 209-210 

Summer, cause of, 60 

Summer solstice, 60 

Sun, distance of, from Earth, 
1-2, 25-27; ancient conception 
of, 2-3; compared with Arc- 
turus, 10; comparative size 
of, 11-12; movement of, 13- 
14; among stars forming 
Milky Way, 16, 197; early 
theories about, 21-23; life on 
Earth dependent on, 23-25; 
weight and composition of, 
27-28; energy and heat of, 
28-32; constancy of heat of, 
32-33; intensity of light of, 
33; spots on, 34; daily rota- 
tion of, 34-35; faculge of, 36; 
corona and prominences of, 
37-39; elements existent in, 
40; lack of knowledge of 
center of, 40-41; planets 
about, forming solar system, 
41-43; tributes to magnifi- 
cence of, 43; revolution of 
Earth about, 52-57; effects 
of Earth's revolution about, 
58-62 ; arrangement of planets 
in relation to, 67-68; influ- 
ence of, on tides, 130; influ- 
ence of, on comets, 138-139, 
141-144, 152-153; relation to 
meteors and meteorites, 180- 
181 

Sunlight, intensity of, 33 

Suns, groups and clusters of, 
188-189 

Sun-spots, explained, 34-36 

Swan, constellation, 186. See 
Cygnus 

Swift's comet, 174 

Tails of comets, 137-139 
Taurus, constellation, 211, 216 
Temple's comet, 174-175 



INDEX 



273 



Temporary stars, phenomenon 
of, 16-19 

Tennyson, Princess, quoted, 221 

Tesla, N., on communication 
with Mars, 97 

Themis, moon of Saturn, 112 

Thomas, Edith M., verse by, 
on Milky Way, 192 

Tides, influence of Moon and 
Sun on, 130; spring and neap, 
130 

Time, measurement of, by rota- 
tion of Earth, 55-57 

Time sections, division of 
United States into, 57-58 

Titan, satellite of Saturn, 70, 
112 

Todd, David, quoted on heat 
of Sun, 30; cited on moun- 
tains of Moon, 123; on dan- 
gers from comets, 151-152 

Transits of planets, 91 

Triesnecker, crater on Moon, 
124 

Twins, the. See Gemini 

Tycho, crater on Moon, 120, 123 

Universe, old theories concern- 
ing, 2-3, 47-50; stability of 
laws of, 62; boundlessness 
of, 242 

Uranolith. See Meteorites 

Uranus, planet, size of, 41; 
distance from Sun, 42-43; 
an outer planet, 68; diameter 
of, 69; satellites of, 70, 115; 
velocity of, 70; period of 
revolution of, 72; color of, 
77, 114; location of, 114; 
dimensions, 114-115; comets 
about, 146 

Ursa Major and Ursa Minor, 
206. See Great Bear and 
Little Bear 



Variable stars, phenomenon of, 

19 
Vega, star, 224, 239 
Velocities of planets, 70-72 
Venus, planet, 10; size of, 41; 
orbit of, 42; derivation of 
name, 47; an inner planet, 
67; diameter of, 69; velocity 
of, 70; distance from Earth, 
72; period of revolution, 72; 
color of, 77; special charac- 
teristics of, 87-91 ; transits of, 
91-92 
Vesta, minor planet, 103 
Virgo, constellation, 211, 236 
Volcanoes of Moon, 121-122 

Water-bearer. See Aquarius 
Weight, measurement of, on 

different planets, 73-75 
Whitman, Walt, quoted, 242-243 
Whittier, J. G., poem by, deal- 
ing with Southern Cross, 
227-228 
Winter, cause of, 60, 61 
Wireless, signals by, from other 
planets, 89-90 

Year, length of, on different 
planets, 72-73; the Martian, 
93 

Zeta, star in Great Bear, 206 
Zeta-Cancri, quadruple star 

system, 187 
Zodiac, defined, 228; origin of 
term, 229; locating the con- 
stellations in, 230-231; dis- 
tinction between constella- 
tions of, and signs of, 231- 
232; order of stars in the, 
233 
Zodiacal light, cause of, 170-171 
Zodiacal region, the, 101 



AUTUMN 




South 
MAP OF THE STARS, 12 P.M., OCTOBER 



WINTER 




South 

MAP OF THE STARS, 12 P.M., JANUARY 



